HOW TO ESTIMATE THE COST OF T-BAR

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1 HOW TO ESTIMATE THE COST OF T-BAR ACOUSTICAL CEILINGS MICHAEL HILL DATE WRITTEN: MAY OF 2007 The author is Michael Hill, Estimator with Kaiser Foundation Hospitals, National Facilities Services Cost Engineering Group. Michael has been a member of ASPE since Michael has more than twenty-five years experience in the construction and remodeling of hospitals and office buildings. Experienced in all phases of construction including design, computer aided drafting (CAD), space design, estimating, scheduling, presentations, project management, supervision and project inspections. Michael has worked in the construction business with his father, a general contractor, and then for Kaiser Foundation Hospitals as a journeyman carpenter in Since then he has been in engineering, worked as a CAD (computer aided drafting) designer, designed databases for work order and equipment tracking, a project superintendent, a project manager, a space designer and an estimator. The Cost Engineering Group Michael works with oversees the maintenance and renovation estimating for eleven of the Kaiser Permanente Medical Centers. TABLE OF CONTENTS INTRODUCTION Main CSI Division Specific Subdivision/ Specification Section Brief Description TYPES AND METHODS OF MEASUREMENT Material take-off review FACTORS THAT AFFECT TAKE-OFF, PRICING, ETC Small versus large quantities Geographic location OVERVIEW OF LABOR, EQUIPMENT, MATERIAL, AND INDIRECT COSTS Sample of production rates SPECIAL RISK CONSIDERATION RATIOS AND ANALYSIS TOOLS TO TEST FINAL BID MISCELLANEOUS PERTINENT INFORMATION Sample ceiling specifications CONCLUSION DETAIL SHEETS Sample sketch Sample take-off sheet Sample pricing INTRODUCTION This paper will address the materials and methods used in cost estimating for acoustical suspension ceilings with acoustic ceiling tiles (commonly called T-bar because of the T shaped supports). The T-bar acoustical ceiling system is an extremely versatile product. Buildings that commonly use T-bar acoustical ceilings are commercial buildings, hospital buildings, schools, and residential modular homes. T-bar acoustical ceiling systems can be installed in all types of structures made from wood, metal, steel and concrete. Main CSI Division Division Nine, (9) Finishes Subdivision Specification Section Metal Support Assemblies Acoustical Suspension Specification Section Ceilings Acoustical Ceiling Brief Description The T-bar acoustical ceiling system provides the following benefits; sound attenuation, access to utilities above, architectural design enhancement, ease of maintenance, ease of replacement of tiles, suspension of lighting and room utilities. The T-bar grid system consists of main runners, cross runners, wall angles, support wires and struts. There are many methods used to install the T-bar grid system, depending on the system and design requirements. For example support wires are dropped through the pan-deck, shot in the ceiling using power actuated fasteners or anchored using drilled expansion anchors (see Details 3 & 5). The sections of anchored wires are then tied to the T-bar (see Detail 2). Additional grid wires are also installed to support other trade s ceiling installed items. For example light fixtures and HVAC (heating ventilation & air conditioning) registers which are also laid into the finished grid system. Acoustic tiles are then placed into the grid along with the other trades items to finish the ceiling work. Many tiles will need to be cut to provide openings needed for fire alarm, fire sprinklers, special lighting cans and security components. The support elements of these components are usually provided by the other trades and are not figured in the estimate. Acoustic tile sizes and material vary greatly depending on usage. Sizes include: 24 x 24 panels and 48 x 24 panels. There are fire rated tiles, fiberglass, plastic coated, aluminum and material fiber tiles in many styles and colors. There are also tin tiles with hundreds of patterns and colors. T-bar grid also comes in a variety of materials and colors. This paper will only review the heavy-duty T-bar acoustical ceiling system. Materials required to build a T-bar ceiling include: 1) Hanging wires Estimating Today 17 PDF processed with CutePDF evaluation edition

2 2) Seismic posts 3) Wall angle 4) Main runners 5) Cross runners 6) Acoustic drop in panels TYPES AND METHODS OF MEASUREMENT Methods used to create a material take-off used by T-bar acoustical ceiling estimators, are accomplished by using the following units of measurement: square feet, item count and linear feet. Direction of tiles needs to be reviewed. The layout of fire sprinklers, HVAC registers, lighting and fire alarm work all needs to be reviewed. Often the T-bar ceiling subcontractor is asked to supply and install hanger wires for the other trades. Information needed to estimate quantity of support wire counts, needs to include HVAC registers and light fixtures. Material take-off review The material take-off is done by first measuring the room for width and length. Material can be figured using a spreadsheet with calculations added (see Sample Material Take-off). AREA Area is calculated width of room multiplied by the length of room. PANEL Panel count is calculated Divide area by eight square feet for 2 X4 ceiling panels (subtract light and HVAC register square footage). MR Main runners are calculated in linear feet Area divided by four. CR 4 Four foot cross runners are calculated Main runners multiplied by two. CR 2 Two foot cross runners are calculated 2 x2 lights and HVAC registers multiplied by two. WA Wall angle length is calculated Width of room plus length of room multiplied by two. Note: The wall angle length may vary depending on the amount of cuts in a room, so a linear foot take-off may be required here. 2 STRUT Two foot strut calculation Width of room divided by two. 4 STRUT Four foot strut calculation Width of room divided by two. V WIRE V wire (vertical) is calculated - Main runner total length divided by four. P WIRE P wire (perimeter) is calculated Width of room divided by two plus length of room divided by four multiplied by two. Example: (W/2+L/4)x2. S POST S WIRE S LIGHTS 2X4 LIGHTS 2X2 HVAC S Posts (seismic) are calculated Area divided by 96. wire (seismic) is calculated Total S posts multiplied by five. Lights are counted from the reflected ceiling plan and multiplied by eight square feet. Lights are counted from the reflected ceiling plan and multiplied by four square feet. HVAC (heating ventilation & air conditioning) registers are counted from the reflected ceiling plan and multiplied by four square feet usually. There are many styles of registers, including 4 slot registers, that will needed to be reviewed so your take-off reflects the required wires and runners. Additional materials that need to be figured for the estimate includes the wall angle fasteners, pop and grid fasteners. These items are calculated on the Pricing sheet along with labor, taxes and mark-up. Wall angle fasteners are calculated One for each wall angle. Pop and grid fasteners are calculated Wall angles divided by five. FACTORS THAT MAY AFFECT TAKE-OFF, PRICING, ETC. Small versus large quantities of material can affect the overall productivity on projects. Factors that may affect productivity include manpower, material, jobsite stocking and equipment. Shop drawings, engineering and sub consultants may be required on larger projects. Large projects can increase installation efficiency by assigning labor to specific tasks and for use of full days to complete tasks. Material can be stock piled on larger projects where there is room to do so. If man lift equipment is required, larger projects may increase installation productivity. Some buildings have continuous T-bar grid systems with walls that abut the ceiling. These walls will not have edge support angles except at firewalls or exterior walls, where the wall runs above the ceiling. On small projects the material quantity minimum purchase may exceed the actual quantity needed for installation. Smaller rooms use more wall angles per square foot. The estimator may need to include a full days pay for a partial days work. Geographic location does affect the labor and material costs of any project. This needs to be reviewed prior to finalizing the estimate. Geographic location is affected mostly on small projects. Travel time may also need to be included due to distance between small projects. Local labor availability, skill levels & cost per hour are also factored into costs. Material and Labor rates are always factored into the estimate and should reflect local costs. Uniform Building Code and state building code standards are to be reviewed, as some states may have other requirements. Commonly, the grid system is installed in an enclosed envelope of the building so weather is not a large consideration. However, support wires are typically installed in a new building after structural steel and pan deck are in place. In cold or windy weather this could affect the installation efficiency. OVERVIEW OF LABOR, EQUIPMENT, MATERIAL AND INDIRECT COSTS The T-bar acoustical ceiling systems are available in many styles many, which require special installation procedures and 18 Estimating Today

3 production costs. This paper will only review the heavy-duty T- bar acoustical ceiling system. A review of the construction documents will reveal conditions that will determine the production costs, type of material, equipment and any indirect costs. A hospital will require additional labor due to the need for drilled inserts for the seismic wires. Also, a hospital demands additional wire supports due to the additional HVAC ducts in the plenum above. For standard commercial applications, powder-actuated fasteners are used. Sample of production rates The information below is used in the example-pricing sheet (see page 26) One man can install about 300 wires a day, using a power actuated fastener or drill. One man can install about 60 wires a day using drilled in expansion anchors. Wires will be about 25% of the overall area. (100 square feet has approximately 25 wires). Grid installation rate is about 600 square feet per day, per man. One man can install approximately 800 square feet of drop in tile per day. One man can install approximately 25 seismic posts per day. One seismic post is required every 96 square feet of area. Wall angle installation is approximately 300 linear feet per day. Wall angle is approximately 25% of the area. (1,000 square feet has approximately 250 linear feet of wall angle). Journeyman Carpenter cost in the San Francisco Bay Area including burden is, approximately $ per day *. installations and ceiling panel installations, which means labor will need to be on hand and ready when other trades are complete (labor will have to come back twice to complete the ceiling work). Going on a job walk of the site to review conditions can eliminate many risks. RATIOS AND ANALYSIS TOOLS TO TEST FINAL BID Reviews of past projects of a similar type can be gathered. Historical data is used for ratios and reviews. This is particularity useful when figuring for man-hours and material. Projects may vary greatly depending on scope. Maintaining historical data from previous projects and post construction evaluations will support new estimates with true baseline information. Many percentages will hold true and assist in the analysis of the estimate. Post construction evaluations are preformed after your project is completed. This evaluation is a useful tool in looking into costs incurred, processes, products, services and review of any errors or changes from your final estimate. This process allows you to learn the best practices to estimate future projects. You will need to evaluate your final estimate versus actual costs, general requirements, direct costs, schedule impacts and change orders that affected the ceiling work. In a post construction evaluation you can review your production rates and update them as needed. Many computer programs can utilize this historical data to graph a project, creating a visual representation. The following Figures No. 1 and No. 2 show the sample pricing sheet (see page 26) percentages in two different formats. The sample displays the ratios of tasks needed to complete the estimate. SPECIAL RISK CONSIDERATION Risk considerations include: Schedule of work. Phasing of the project. Relationships with bidding general contractors and access to project location. Types of ceiling installations. Deck structure & material. Wall type. Anchor type. Grid type. Ceiling tile style. All the items above factor into the final costs and must be reviewed prior to completing the estimate. Complex ceiling designs will also need to be reflected in the estimate such as, curves, soffits, special curtain and lighting. Other trade commodities and their schedule can affect the estimate, including light fixture wires and installation of HVAC register wires. When reviewing the contract documents the reflective ceiling plan is the main drawing for review, it is also prudent to review the plumbing, HVAC and electrical drawings prior to completion of your take-off. A review of the ceiling specifications of a project is also required as they may explain items not shown on the plans (see Sample Specification). Schedules may indicate large periods between support wire Figure No. 1 Figure No. 2 Estimating Today 19

4 MISCELLANEOUS PERTINENT INFORMATION This paper is a review of how to estimate a T-bar acoustical ceiling system. The larger ceiling contractors utilize take-off digitizers and estimating programs. On Screen is the take off program of choice and Quick Bid is an estimating program that is very popular. The choice of which program or take-off method used depends on your company and specific type of work. Your company and labor resources will determine which method works best to meet the project needs. SAMPLE CEILING SPECIFICATIONS Ceiling Notes For Metal Suspension System For Lay In Panel Ceilings: Provide metal suspension system for lay in panel ceilings as follows: General: Requirements for design and installation of suspended acoustical ceiling systems are contained in the Uniform Building Code, and in the building code standards of the local state that work is being completed. 1.0 Ceiling Notes: The following notes are examples of specifications for ceiling systems whose total weight, including air conditioning grills and light fixtures, does not exceed four pounds per square foot. Heavier systems and those supporting lateral loads from partitions will require special design details gauge (minimum) hanger wires may be used for up to and including 4-0 x 4-0 grid and shall be attached to main runners (see Detail 2). 1.2 Provide 12 gauge hanger wires at the ends of all main and cross runners within eight inches (8 ) of the support or within one-fourth (1/4) of the length of the end tee, whichever is least, for the perimeter of the ceiling area. In some cases end connections for runners, which are designed and detailed to resist the applied vertical and horizontal forces may be used in lieu of the 12 gauge hanger wires, subject to review and approval. 1.3 Provide trapeze or other supplementary support members at obstructions to typical hanger spacing. Provide additional hangers, struts, or braces as required at all ceiling breaks, soffits or discontinuous areas. Hanger wires that are more than 1 in 6 out of plumb are to have counter-sloping wires. Obstructions such as large ductwork will require extra wires and will need to be added to the take-off. 1.4 Ceiling grid members may be attached to not more than 2 adjacent walls run diagonally to ceiling grid members shall be at least 1/2 inch free of other walls. If walls run diagonally to ceiling grid system runners, one end of main and cross runners should be free, and a minimum of 1/2 inch clear of wall (see Detail 2). 1.5 At the perimeter of the ceiling area where main or cross runners are not connected to the adjacent wall. Provide interconnection between the runners at the free end to prevent lateral spreading. A metal strut or a 16-gauge wire with a positive mechanical connection to the runner may be used (see Detail 1). Where the perpendicular distance from the wall to the first parallel runner is 12 or less, this interlock is not required. 1.6 Provide bracing assemblies consisting of a compression strut and four (4) 12 gauge splayed bracing wires oriented 90 degrees from each other at the following spacing (see Detail 1). 1. Place bracing assemblies at a spacing not more than 8 feet 12 feet on center. 2. Provide bracing assemblies at locations not more than one-half (1/2) the spacing given in 1 (1.6) 1 above from each perimeter wall and at the edge of vertical ceiling offsets. The slope of these wires shall not exceed 45 degrees from the plane of the ceiling and shall be taut. Splices in bracing wires are not to be permitted without special approval. 4. Suspended acoustical ceiling systems with a ceiling area of 144 square feet or less, and fire rated suspended acoustical ceiling systems with a ceiling area of 96 square feet or less, surrounded by walls which connect directly to the structure above, do not require bracing assemblies when attached to two adjacent walls. 1.7 Fasten hanger wires with not less than three (3) tight turns (see Detail 5). Fasten bracing wires with four (4) tight turns (see Detail 3). Make all tight turns within a distance of 1-1/2 inches. Hanger or bracing wire anchors to the structure should be installed in such a manner that the direction of the wire aligns as closely as possible with the direction of the forces acting on the wire (see Details 3 & 5). Note: Wire turns made by machine where both strands have been deformed or bent in wrapping can waive the 1-1/2 requirement, but the number of turns should be maintained, and as tight as possible. 1.8 Separate all ceiling hanging and bracing wires at least six inches (6 ) from all un-braced ducts, pipes, conduits, etc. It is acceptable to attach lightweight items, such as single electrical conduit, not exceeding 3/4 nominal diameter, to hanger wires. 1.9 When drill-in concrete anchors or shot-in anchors are used in reinforced concrete for hanger wires, 1 out of 10 must be field tested for 200 pounds of tension, when drilled-in anchors are used for bracing wires, 1 out of 2 must be field tested to 440 pounds in tension. Shot-in anchors are not permitted for bracing wires. If any shotin or drilled-in anchors fail, a review of local building codes will be required. Note: Drilled-in or shot-in anchors will require special approval when used in pre-stressed concrete Attach all light fixtures and ceiling mounted air 20 Estimating Today

5 terminals or service, to the ceiling grid runners to resist a horizontal force equal to the weight of the fixtures. Screws or approved fastener are required Flush or recessed light fixtures and air terminals or services weighing 56 pounds or more must be supported directly on the runners of a heavy duty grid system but, in addition, they must have a minimum of two 12 gauge slack safety wires attached to the fixture at diagonal corners and anchored to the structure above. All flush or recessed light fixtures and air terminals or services weighing 56 pounds or more must be independently supported by not less than four (4) taut 12 gauge wires each attached to the fixture and anchored to the structure above regardless of the type of ceiling grid system used. The four (4) taut 12 gauge wires including their attachment to the structure above must be capable of supporting four (4) times the weight of the unit. SUSPENDED CEILING BRACING ASSEMBLY DETAIL Support surface mounted light fixtures by at least two positive devices which surround the ceiling runner and which are each supported from the structure above by a 12-gauge wire. Spring clips or clamps that connect only to the runner are not acceptable. Provide additional supports when light fixtures are 8 feet or longer Support pendant mounted light fixtures directly from the structure above with hanger wires or cables passing through each pendant hanger and capable of supporting four (4) times the weight of the fixture. A bracing assembly is required where the pendant hanger penetrates the ceiling. Special details are required to attach the pendant hanger to the bracing assembly to transmit horizontal forces Classification of ceiling grid (Manufacturer) - Classification of ceiling grid is heavy duty for this paper. - Manufacturer s catalog number - main runner - heavy duty. - Manufacturer s catalog number - cross runner - heavy duty. - Manufacturer s catalog number of detail for runner splice (see Detail 6). CONCLUSION In summary, this paper explains how to estimate the cost of T- bar acoustical ceilings. There are many factors that affect your take-off. For example, the project size, geographic locations and special risk considerations. In addition, a review of labor, equipment, material, and indirect costs are needed to complete the T-bar acoustical ceiling estimate. The types and methods of measurement used for take-offs are item count, square footage and linear footage. Lastly, an estimator should incorporate historical ratios and analysis tools to test final bid. HANGER WIRE CONNECTION TO GRID DETAIL 2 Estimating Today 21

6 SIESMIC (SPLAY) WIRE ATTACHMENT DETAIL 3 RUNNER SPLICE DETAIL 6 HANGER WIRE SPLICE DETAIL 4 VERTICAL WIRE ATTACHMENT DETAIL 5 22 Estimating Today SAMPLE SKETCH

7 SAMPLE TAKE-OFF AND PRICING SHEETS (See material take-off review for details) ** Carpenter Northern California trade union agreement with AGC dated January Estimating Today 23