5.0 wall ApplicAtions

Transcription

1 5.0 Wall Applications

2 5.1 Below Grade Walls Properly reinforced Arxx ICFs with a nominal concrete core width of 6 (150 mm) are demonstrably more resistant to lateral earth pressures than 8 (200 mm) plain or lightly reinforced cast-in-place concrete basement walls or reinforced concrete masonry walls. Codes dictate that all below grade walls, with habitable space on the interior side of the wall, shall have waterproofing or damp-proofing systems installed to the height of the finished grade level. Waterproofing or damp-proofing is optional for below grade walls that have earth on both sides and are not habitable space. Refer to 5.2 Below Grade Moisture Protection Below grade walls require floor anchor connections, such as anchor bolts or ICF ledger connectors, installed either in the top of the wall or in the side of the wall forms. It is not recommended to backfill against a below grade wall until the wall is laterally supported at the top with a floor system. In addition, the concrete should be allowed to cure a minimum of 7 days prior to backfilling. Foam plastic insulation needs to be separated from the interior of a building by an approved thermal barrier of ½ (12.7 mm) gypsum board or an equivalent thermal barrier material. Check local codes for approved materials and exceptions. Check local building codes for anchorage or design requirements regarding connecting the top of the walls to the floor or roof systems. Depending on the building code, a variety of anchors and straps will be required be inserted into the concrete Below Grade Walls

3 5.2 Below Grade Moisture Protection Overview For all below grade applications, building codes require that walls that have retained earth and enclosed interior space must be waterproofed or damp-proofed. It is recommended that any waterproofing product used must be EPS compatible. There are many waterproofing products available that have been developed for application on ICFs and are EPS compatible. The types of waterproofing developed for ICF walls are: peel and stick membrane, liquid applications that are sprayed, rolled or troweled on the wall, and dimple type drainage mats, which are fastened to the wall. All applications must follow the manufacturer s installation specifications and recommendations. Waterproofing works best when the waterproofed wall is backfilled with free draining backfill material such as sand and gravel. The use of backfill protection board is also strongly recommended to protect the membrane from being punctured by any deleterious material such as rocks, etc., which may be present in the backfill. It is recommended to follow the waterproofing system manufacturer s recommendations for the application of a protection board over the waterproofing system. Solvent based products are not recommended, as they damage the EPS Preparation for Below Grade Moisture Protection Installation of a waterproofing membrane works best when the site is dry and temperatures are between 40 and 80 F (5 and 27 C). In temperatures below and above these conditions, refer to the manufacturer s installation instructions. The wall and footing surfaces should be smooth, clean and dry, free of dirt, loose aggregate or other foreign materials, voids, sharp protrusions and contaminants such as wax, oil, silicone or pigments. Any yellow dusting of EPS foam as a result of exposure to UV, must also be cleaned off before any adhesive type product can be applied. In addition, concrete footing surfaces should be cured for 7 days minimum before installation takes place to promote maximum adhesion of the product to the footing surface. If the walls have been exposed to heavy rains, adequate drying time should be allowed before the application of a waterproofing membrane. The manufacturer s specifications should be referred to. For certain conditions, some products recommend a primer material be applied to the wall. Primers must also be compatible with EPS. The manufacturer s specifications should be referred to Installation of Below Grade Moisture Protection Waterproofing systems are typically installed from the final grade level, around the perimeter of the building, down to the top level of the footing, and if possible, over the flat surface of the footing, which will direct any water draining down the face of the system into the building s perimeter drainage system. Any service penetrations, below grade windows in window wells, or other penetrations in the concrete, must be sealed adequately to be watertight. 5.2 Below Grade Moisture Protection 99

4 If applying below grade moisture protection in cold temperatures, i.e. below freezing and up to 50 degrees F (below 0 and up to 10 degrees C), walls should be checked for frost and temporary tenting and heating may be required. In these conditions, the application steps should be confirmed with the manufacturer of the materials. If applying moisture protection in extremely hot temperatures, temporary shading may be required. Before performing the backfill, it is recommended to inspect and confirm that the waterproofing system is ready. Care should be taken to ensure all below grade service penetrations are sealed properly. It is not recommended to leave waterproofing materials exposed to the ultraviolet rays of the sun for extended periods. The manufacturer s recommendations should be checked to confirm exposure details. Some waterproofing systems are recognized as termite resistant barriers, and they are recommended for use in areas at risk for termite infestation. Refer to Appendix B: Termite Section. All waterproofing/damp-proofing systems must be compatible with ARXX ICFs and EPS foam. All warranties for waterproofing/damp-proofing are provided by the respective manufacturer of the waterproofing/ damp-proofing system Parging or Cementitious Coating The below grade waterproofing system typically terminates around the building at the finished grade level, and per the building code, the start of the exterior finish may be between 6 to 16 (150 to 406 mm) above the finished grade. Since long-term exposure to ultraviolet rays oxidizes the EPS, it is recommended to provide coverage for this exposed portion of the ARXX wall. This area of the wall is most often covered with a directly applied transition material or parging. Transition materials are designed specifically for this application. They may be peel and stick membranes, pre-finished sheet goods, cement board, etc. Typically, parging is a cementitious or acrylic stucco material, directly applied to the ARXX form. There are a number of materials available for this purpose that may be directly applied to ARXX walls. It is recommended to follow the manufacturer s installation specifications and recommendations, including confirming that the materials are compatible with EPS. The application of this transition material must maintain the drainage plane for moisture from the above grade wall cavity or face of the EPS behind the exterior finishing material, to the exterior face of the below grade waterproofing system. To accomplish this there may be an overlap of materials Below Grade Moisture Protection

5 Figure Parging Before applying a cementitious or stucco type parge coat, the EPS wall surface must be free of any dirt, debris, or UV oxidation, to allow proper adhesion of the parge coat material. In addition to the requirements identified in this section, the material and application selected should have the ability to withstand abrasive contact from landscaping equipment, i.e lawnmowers and edge trimmers. Damage may allow moisture to penetrate the wall system. A building envelope is designed to resist and prevent moisture intrusion. The parging and the below grade waterproofing systems are integral parts of the design; they must work together successfully as part of the overall moisture protection and drainage systems. All parging or coating systems must be compatible with ARXX forms and EPS foam. 5.2 Below Grade Moisture Protection 101

6 5.3 Grade Beams Due to soil conditions in some North American geographical regions, it is necessary to provide a foundation system that can withstand the forces imposed by shifting soils. Traditional footings require the soils below them to have a bearing capacity sufficient to support the loading conditions of the building, but some upper zone soils cannot support such loads, making it necessary to transfer the loads to the soils or rock below, which can provide the appropriate support. This can be accomplished by placing piles through the weaker soils to rest on either bedrock or soil with a greater bearing capacity. When installing piles, the ICF walls must be designed to span, or bridge, from pile to pile. Installing void forms between the piles is the simplest method to support a wall that spans piles. The ARXX forms are placed on top of the void forms, allowing the soil beneath it to expand without moving the foundation wall. ARXX ICFs may typically be designed as a two course grade beam that spans between the piles, but in some applications may require multiple courses or may incorporate these beams into the full wall design. Grade beams should be designed by design professionals. Similarly, two course bond beams can be installed on raised piles in flood zones or coastal areas. Bond beams require convention forming systems between the piles under the ICF wall. Figure Typical Grade Beam on Piles Grade Beams

7 5.4 Shallow Foundations Generally, footings are installed below the frost line, as determined by national and local building codes. However, the building code also provides an alternative solution with shallow footings and foundations. ARXX ICFs contribute to the design of shallow foundations by insulating the foundation wall from the top of the footing, restricting cold and frost through the foundation wall, and protecting the floor slab. In addition, the installation of below grade rigid insulation that is parallel to the finished grade, protects the footings from frost. The design parameters of the thickness, width and depth below grade of the insulation depend on the climate zone. Figure Shallow Foundation 5.4 Shallow Foundations 103

8 5.5 Stem Walls Stem walls are foundation walls that are typically two or three courses with unbalanced fill that can be on either side of the wall. ARXX forms are recommended for the construction of stem walls Stem Walls for Concrete Slabs A concrete floor slab may either bear on top of the stem wall or integrate into the stem wall. In both cases, the concrete slab is connected to the ICF wall with rebar dowels, which provide lateral support for the top of the stem wall. It is recommended to provide temporary support or bracings for the outside of stem walls prior to the placement of the concrete floor slab Stem Walls for a Crawl Space ARXX ICFs provide insulated foundation walls for crawl space applications. Provisions in the building code allow ARXX ICF crawl spaces to be left unfinished, without the application of a thermal barrier, if the following applies: Entry to the crawl space is only to service utilities and there are no heat producing appliances. There are no interconnected basement areas. Air in the crawl space is not circulated to other parts of the building. ARXX ICFs can easily accommodate the installation of crawl space vents and flood vents, which can be manufactured specifically for ICF walls. The floor system bearing on top of and connected to the ARXX ICF stem wall provides the required lateral support for the wall. The construction of a pony wall installed on top of an ARXX ICF stem wall does not provide lateral support for the foundation wall. In order to design the foundation wall as a retaining wall, additional structural design is required, typically requiring a minimum 8 (200 mm) flat wall ICF concrete core. Foundation walls that do not have habitable space on one side, do not require waterproofing/dampproofing Stem Walls

9 Figure Slab on Stem Wall Figure Slab Poured into Top Edge 5.5 Stem Walls 105

10 Figure Slab into Side of Stem Wall Figure Crawl Space Stem Walls

11 5.6 Columns and Pilasters Depending on the engineered size of a column or a pilaster in a wall, they can be formed easily in a number of ways. It is recommended that columns and pilasters are formed so that they integrate with the wall design. Ideally, they should have their concrete placed at the same time as the ARXX wall Internal Columns and Pilasters An internal column or pilaster is an enlargement of the concrete core, built to meet structural requirements, but minimizing the projections either to the interior or the exterior of the wall. By removing sections of EPS from the ARXX form on either one or both sides, the overall concrete core can increase respectively by a 2½ or 5 (63.5 mm to 125 mm). This equates to having a column or pilaster available to any width with a nominal concrete core thickness as follows: Table Columns and Pilasters Thickness Form Concrete Core One Side Two Sides 6 (150 mm) 8 1/2 (216 mm) 11 (279 mm) 8 (200 mm) 10 1/2 (267 mm) 13 (330 mm) 10 (250 mm) 12 1/2 (317 mm) 15 (381 mm) When cutting only one side of ICF to create a pilaster, it is recommended to cut the interior face of the form, which keeps the insulation value on the exterior and maintains a continuous substrate for exterior finishes. Individual columns or pilasters may be designed to support point loads on the wall from a beam. 5.6 Columns and Pilasters 107

12 5.6.2 Installation Method for Columns and Pilasters Once the wall is built, the block in the designated area should be cut vertically to the design width of the column or pilaster. When only cutting one side of the form, any webs should be cut back so that they are not in the way but enough of the web should be left to use to fasten ties, if required. ¾ (19 mm) plywood should be installed across the opening, as this will hold each side of the wall in place and restrain the concrete. Strapping and bracing should then be installed as required to ensure the two wall sections remain in line and are plumb. Once the concrete has been placed and cured, insulation may be glued to the exposed concrete. Figure Internal Pilaster Details Figure Column Detail Columns and Pilasters

13 5.6.3 Larger Columns and Pilasters When larger columns or pilasters are required, modified corner forms or ARXX Edge panels can be used to form the column or pilaster. ARXX Prime and ARXX Steel corner forms can have their interior panels cut off to form a column or pilaster. Care should be taken to leave enough of the web on the panel to fasten ties. Figure Edge Corner Column Figure Edge Panel Column ARXX Edge panels can be used with any ARXX form to create a column or pilaster. Rather than building a column or pilaster with corner forms, ARXX Edge panel connectors can be used on all the corners to connect standard form panels and provide space for columns or pilasters. When possible, it is recommended to use ARXX Edge tie anchors to tie the panels together. Due to the additional concrete placed in a column or pilaster, more pressure is applied to the forms, so adequate strapping and bracing is required at all corners and joints. Depending on the width of the column or pilaster, conventional concrete forming at the column or pilaster may be required to withstand the concrete pressure. Column and pilaster sizes and footing depth must be designed, engineered, and constructed in accordance with all applicable building codes and regulations. Columns or pilasters may require additional vertical rebar and/or cage stirrups. 5.6 Columns and Pilasters 109

14 5.7 Above Grade Walls ICFs are recognized as a concrete forming system for above grade walls and have been adopted in national and local building codes as a viable alternative to conventional framing or masonry construction for all building types. The installation of ARXX forms for above grade applications is essentially the same as it is for below grade applications; however, due to different loading conditions, the reinforcing patterns and the form size may be somewhat different. Generally, above grade walls contain more window and door openings than below grade walls, or foundation walls, and the design must incorporate the distribution of loads at these openings with specific lintel designs. Above grade wall design is also subject to seismic loads, wind loads, snow loads and superimposed loads from the roofing, additional floors, etc. It is recommended that care be taken to identify and address all of the load conditions that may have an impact on the wall design, as these conditions influence form size, wall height, and the appropriate reinforcements around all the openings and under point load items, including beams, girder trusses, etc. Above grade walls may have smaller form sizes than below grade walls, which will call for a transition in form sizes. Form size transitions are accommodated in the floor intersection detail. Typically, concrete is placed in the below grade walls first with a cold joint connection to the above grade walls. Cold joints are also between each story in above grade multi story applications. Refer to Section for details on cold joint reinforcing between the foundation wall and the above grade wall. All openings greater than 24 (610 mm) in width will require additional reinforcing at the sides and below and over the opening (refer to Appendix A - A.6 Lintel Design). Reinforcement in above grade walls is placed in the center of the concrete core. The placement of the horizontal rebar should be alternated to allow the vertical rebar to interlace between the horizontal bars. It is recommended that the first course of the above grade wall be secured to the top course of the below grade wall with tie-wire, zip-ties or ARXX hooks. When a wall is to be continued for further stages, it is recommended to leave the concrete approximately 8 (203 mm) from the top of the wall, so that the top half of the web is exposed above the concrete. Leaving the web exposed will allow the installer to tie down the first course of the next stage the wall. To support and fasten alignment bracing systems for above grade walls, it is recommended that sub-floors be installed first, in order to provide a suitable substrate. Concrete walls cannot be supported on wood framing Above Grade Walls

15 Refer to local building codes for regulations on reinforcement for above grade walls. Foam plastic insulation needs to be separated from the interior of a building by an approved thermal barrier of ½ (12.7mm) gypsum board or an equivalent thermal barrier material. Check local codes for approved equivalent materials and exceptions. Check local building codes for anchorage or design requirements to connect the top of the walls to the floor or roof systems. Depending on the building code, a variety of anchors and straps will be required to inserted into the concrete. 5.8 T-walls or Intersecting Walls T-walls are walls that intersect each other, typically at a 90 angle. Although these walls are generally an interior wall intersecting with an exterior wall, they can be any two walls. T-wall intersections can be anywhere in the run of the main wall, requiring that a web be cut out at the intersection location. T-walls can be the same or different concrete core sizes. T-walls are easy and efficient to build. They are typically constructed as vertical joints, butting the forms together and then fastening them together. Each of ARXX s form product lines, Edge, Prime and Steel, has slightly different application to create a T-wall intersection, but in all cases, the following design and construction issues must be addressed: Providing for additional concrete pressure on the exterior wall panels. Securing each form to the main wall. Ensuring that the horizontal rebar lap joint is through the intersection. Maintaining a square inside corner. Ensuring support on the vertical joint for concrete placement. The following installation steps apply to all T-walls that have an interior wall intersecting an exterior wall: 1. The intersection must be located and then the intersecting form placed against the exterior wall and two cut lines marked, for core size, against the exterior wall. 2. The exterior form is cut along the cut lines. If the cut exposes a web, most of the web is removed, but leaving enough web in the wall to fasten the intersecting forms with tie-wire or zip-ties. The ARXX Edge panel connector is compatible with all ARXX forms, and it can be used for T-wall applications for any ARXX form products. Due to concrete pressure, external bracing is recommended for T-walls. 2 x 6 (38 mm x 140 mm) or larger dimension lumber or plywood should be used to vertically support the forms at the T intersection. If vertical bracing support cannot be applied, then horizontal strapping across each form should be installed. When placing concrete in the intersecting walls, the pressure can be minimized by placing the concrete on the straight wall and allowing the concrete to flow into the T-wall. 5.8 T-walls or Intersecting Walls 111

16 5.8.1 ARXX Edge T-walls The construction of a T-wall with ARXX Edge panels uses ARXX Edge tie anchors and ARXX Edge panel connectors. The constructions steps are as follows: 1. The two ARXX Edge panel connectors are installed and the standard panels are inserted. 2. If the web in the exterior panel lines up within the intersecting core, ARXX Edge tie anchors are inserted in the first, third and fifth tees in the web of the exterior wall panel. 3. If the web in the exterior panel is offset by more than 3 (75 mm) from the centerline of the intersecting wall, then a 36 (915 mm) long piece of rebar is attached to the top and bottom connectors using tie-wire, in the outside notch of the exterior wall panel. The two web connectors of the intersecting forms are tied around the rebar and the forms pulled together. 4. If the web in the exterior panel lines up near the center of the intersecting wall, the spacing of the first row of web connectors in the intersecting form should be revised so that there are three connectors, at the first, third and fifth tees. 5. Using tie-wire or zip-ties in each of the three tie anchors, the ties are run around the web connectors in the intersecting form. The ties can be used to evenly pull the forms together. It is not recommended to overly tighten the ties, as they will deflect the wall panels. 6. The horizontal rebar can be installed as required. Figure ARXX Edge T-wall Above Grade Walls

17 5.8.2 ARXX Prime T-walls 1. Two 24 (610 mm) long pieces of rebar should be inserted in the top and bottom of the outside triangle of the web of the exterior wall form. Ties around the rebar to the web in the intersecting form can be used to evenly pull the forms together. It is not recommended to overly tighten the ties, as they will deflect the wall panels. 2. The horizontal rebar can be installed, as required, in each course. 3. When the full wall is built, the vertical joints should be secured with glue or bracing prior to concrete placement and care taken to ensure that the vertical joints are plumb. Figure ARXX Prime T-wall Use panel connectors ARXX Steel T-walls 1. The vertical tongue and groove edge from the intersecting form should be removed to create a flat edge. 2. An 18 (457 mm) piece of rebar should be inserted through the web grid of the exterior form. This bar will be pulled tight against the form and should span over a minimum of four webs. 3. Tie-wire or zip-ties should be fastened around the rebar into the third or fourth web of the intersecting form and the forms pulled together evenly. Care should be taken to ensure that the ties are not overly tightened, as they will deflect the wall panels. 4. The horizontal rebar can be installed, as required, in each course. 5. When the full wall is built, the vertical joints should be secured with glue or bracing prior to concrete placement and care taken to ensure that the vertical joints are plumb. 5.8 T-walls or Intersecting Walls 113

18 Figure ARXX Steel T-wall ARXX Steel Waffle T-walls The same procedures in Section for ARXX Steel T-walls should be followed, with the following exception: 1. An opening should be cut in the wall and/or intersecting form in order to match the waffle grid profile. This opening allows for adequate concrete at the joint and an easier flow of concrete through the joint. Figure ARXX Steel Waffle T-wall T-walls or Intersecting Walls

19 5.9 Angled and Radius Walls Angled Walls Forms for walls that have angles other than 90º and 45º will require on-site cutting to create mitered vertical joints. It is recommended to attempt to set the form layout to accommodate cutting the forms without excessive interference with the webs. In most cases, there may be more than 4 (100 mm) from the web on the EPS panel at the outside corner. When constructing a vertical joint, the forms should be tied together with tie-wire or zip-ties, two per course, and the reinforcement bars should be bent to run continuously through the corner. Once the forms are set properly in the wall, the outside corner edge should be glued with low expansion spray foam and/or fiber tape installed with two strips per form, across the joint. Prior to concrete placement, continuous supplemental support is required up the entire wall Radius Walls The construction of radius or curved walls is an easy application using ARXX ICFs, but they do involve more labor to construct. There are two basic methods to build a curved wall: the double segment cut method and the single cut method. It is recommended to consult an ARXX technical representative for the best method to use for each individual radius wall application, as the method chosen is dependent on the curvature of the wall, the form type, and the concrete core size Small Radius Walls Small radius walls have a radius of less than 10 (3 m), and they typically use the double segment cut method. The forms are cut into 8 (203 mm) segments. Outside panels have a simple saw cut through the panel, however, inside panels must be reduced to allow for the tighter curvature. Refer to the ARXX Detail Library for cutting tables per radius. Lay out the curve and install wood blocking along the outside of the curve to hold the forms in place. The first course of cut block segments is then installed forcing them against the wood blocking. Once the first course is in place, the blocks should be glued together and secured to the concrete footings. Subsequent courses are placed exactly like the first course, without an overlap or running bond. Fiber tape or internal ties should be installed to pull the wall segment together, both vertically and horizontally. Prior to concrete placement, each course must be supported to withstand the concrete pressure. The simplest support method is to bend and install 8 to 12 (203 mm to 305 mm) wide plywood strips across the outside of the curve. The center of the plywood should be located on either the horizontal block joint or on the center of the course, and then the plywood strips fastened to the webs. It is recommended to install this temporary strapping on each course. As the curved wall is being built, care should be taken to ensure each course is level. 5.9 Angled and Radius Walls 115

20 Figure Radius Wall Large Radius Walls Large radius walls have a radius of over 10 (3 m), and they typically use the single segment cut method. Depending on the ARXX form type being used, it is recommended to test this procedure before cutting too many forms. The single segment cut method requires only the interior wall panel of the curve to be cut. A small pie shaped piece of foam between each web is removed (see figure ) in accordance with the ARXX Radius Wall Technical bulletin. The ends of the block are also cut accordingly. Once the entire block has been cut on the one side, the block can be slowly bent to fit the curve. Refer to Section Small Radius Walls for the procedure of how to set out the curve and install a wood blocking guide along the outside edge. The full form should be installed against the blocking and the forms secured in place. Once the first course is set, subsequent courses can be installed in a running bond pattern Angled and Radius Walls

21 Figure Panel Cuts Figure Hot Knife Figure Panel Cuts Refer to ARXX Technical Library for radius wall construction details and cutting tables. The wire cutter for the hot knife should be fabricated to the dimension that corresponds to the size of the foam strips being cut out of the inside panel. The wire should be bent to provide a slight angle cut along the foam, which will allow the panels to fit tightly together when curved (figure ). Bending the form produces a perfect radius wall on the outside of the curve for the direct application of stucco finishes. If the inside of the curve is going be a finished wall, the outside panel needs a simple saw cut between webs. Bending the form to suit the radius will open up the cuts on the outside face. The cuts should be filled with spray foam prior to concrete placement. The reinforcement bars should be pre-bent to suit the radius. Care should be taken so that the curved rebar does not act as a spring and alter the form layout. The intersection of a curved wall to the regular wall will create a vertical joint. The procedure for cold joints in Section vertical reinforcement cold joint should be followed image.doc 5.9 Angled and Radius Walls 117

22 Radius Cutting Block Segment Method 1. The radius on the footing or slab should be marked and an 8 (203 mm) segment measured to determine the cut angles. When cutting, the web is to be centered in the segment. Depending on the radius, the edges of each segment may need to be cut on an angle to allow the forms to fit tightly together when forming the curve. Figure Measuring Radius Angles Figure Marking Block for Radius Cuts 2. A block segment should be placed on the chalk lines and cut to the required angles. Figure Radius Block Segments Angled and Radius Walls

23 3. This cut block is used as a template to cut the rest of the block segments to complete the wall. Figure Setting Radius Block Segments 4. The block segments should be stacked, with care taken to align the webs vertically and to connect each segment with zip-ties. 5. As the curved wall is being stacked, care should be taken to ensure that it is level. 6. The forms can be glued into place and any gaps filled with spray foam. 7. Each course of the wall should then be strapped with bendable plywood strips that are 8 to 12 (203 mm to 305 mm) wide. (Refer to Figure ) Figure Tieing Radius Walls 5.9 Angled and Radius Walls 119

24 5.10 Demising Walls A demising wall, or party wall, is an interior wall that separates interior spaces. Depending on design requirements, these walls can be designed as load bearing or non-load bearing, and either with or without a fire resistance rating. ARXX ICF wall assemblies have been tested in accordance with ASTM E119 and CAN/ULC S101 and have attained a Fire Resistive Ratings (FRR) from 2 to 4 hours. This allows ARXX ICFs to be used as interior walls for corridor or demising walls, either as firewalls between fire zones or for individual rooms. Refer to ARXX Technical Library for documentation on fire resistive ratings. ARXX ICF wall assemblies have also been tested for sound attenuation and have achieved above average STC ratings for regular wall design and increased STC ratings for specific wall designs. Due to these increased ratings, the use of ARXX ICF wall assemblies as a sound partition or party wall is an advantage over conventional double stud type wall construction. Interior walls require T-wall connections to the exterior walls, see Section 5.8 T-walls or Intersecting Walls. In order to maintain the structural integrity of walls in a fire situation, ARXX has detailed floor connection requirements available for firewalls between units. Refer to the ARXX Detail Library Fire Resistance ARXX ICFs are certified by Intertek and bear the Warnock Hersey Certification Mark as evidence of compliance with the requirements of building code for flame spread, smoke development, and fire resistive rated assemblies Flame Spread Index (FSI) and Smoke Development Index (SDI) When evaluating building materials for fire safety, many factors are considered, including ignition temperature, smoke toxicity and flame spread index (FSI). The FSI is used to describe the surface burning characteristics of building materials. The testing for FSI is completed in accordance with ASTM E84 in the United States and CAN/ ULC S102.2 in Canada. The most commonly used flame-spread classifications are: Class I or A: 0-25 FSR inorganic materials, such as masonry or tile Class II or B: FSR whole wood materials (wood used in the same form as sawn from a tree) Class III or C: FSR reconstituted wood materials, such as plywood, particle board or hardboard In the United States the IBC requires that foam plastic insulation shall not have a flame spread index of more than 75 and a smoke-developed index of more than 450. ARXX ICFs are in compliance with this code provision having attained a flame spread index of less than 75 in accordance with ASTM E84. In Canada the NBCC requires that foam plastic insulation shall not have a flame spread index greater than 500. ARXX ICFs are in compliance with this code provision having attained a flame spread index of 200 in accordance with CAN/ULC S Demising Walls

25 Fire Resistive Rating (FRR) ARXX ICF wall assemblies have been tested in accordance with ASTM E119 and CAN/ULC S101 and have attained a Fire Resistive Ratings (FRR) from 2 to 4 hours. ARXX ICFs are Certified by Intertek and bear the Warnock Hersey Certification Mark as evidence of compliance with the Fire Resistive Rated assembly listings. ARXX ICFs are also approved for use in non-combustible construction on all building types and for any building height. On an exterior wall with a horizontal fire separation distance of more than 5 (1.5 m) the exterior gypsum board may be omitted. Most fire resistance testing was done using either the 4 or 6 (100 mm or 150 mm) nominal concrete core ARXX forms. The results and certification apply for thicker concrete cores, as long as they follow the same assembly criteria. ARXX ICFs have been approved for use in the construction of an exposed building face (i.e. zero lot line) applications. ARXX has developed approved details with specific wall finishes in order to meet building code requirements for fire separation in non-combustible construction. To meet code, the interior of all ICF walls in habitable spaces must be separated from the building interior with an approved 15 minute thermal barrier, such as ½ (12.7 mm) gypsum board or a code-approved equivalent. ARXX fire resistant wall assemblies typically only require a single layer of regular ½ (12.7 mm) gypsum board to finish an interior wall. Refer to the ARXX Technical Library for documentation on the fire resistant assemblies Gable End Walls Certain building designs call for a pitched or cathedral ceiling. To maintain the insulation value and structural component of ARXX ICF walls, walls for pitched ceilings are continued to the roof ridge, rather than terminating horizontally at the eaves. Achieving this requires that the top of the walls be sloped to match the roof pitch. ICF gable walls typically go to the underside of the roof truss as a fire separation, then the wall passes above the roof line Typical Gable Form Placement To form the gable end, the forms should be laid up in a stepped fashion, and then the roof pitch marked with a caulk line on the wall, indicating a cut line for the top of the wall. When the forms are cut to the necessary angle, dimensional lumber can be attached to each side of the gable to act as supplemental supports for the wall. When preparing to place the concrete, pieces of plywood are cut, approximately 15 (380 mm) wide by 32 (813 mm) long, and fastened to the top edge of the dimensional lumber on each side of the wall. These plywood pieces can restrain the concrete for approximately two or two-and-one-half courses. Typically, concrete placed in gable walls has a lower slump 3 to 4 (75 mm to 100 mm)) than that used for the regular walls, which helps contain the concrete in the sloped wall. The concrete should be placed in smaller lifts, two courses high, and consolidated regularly, especially under the plywood restraining caps. This process is repeated until reaching the top of the gable. The plywood restraining caps and strips of lumber can be removed after the concrete has cured Fire Resistance 121

26 Figure Typical Gable End Care should be taken to allow for the installation of anchor bolts or roof connectors as the gable end is built. The gable end wall must be adequately braced and supported Alternate Gable Framing Alternatively, gable ends can be formed without cutting the forms on a slope. The wall forms can be stacked to create the general shape of a gable by inserting end caps and the concrete is prevented from spilling out the ends of the forms. After the concrete is completely placed, the top of the wall can be framed-in with lumber to match the roof trusses or rafters Gable End Walls