B Renton Avenue S Condition Assessment

Transcription

1 TO Mr. John Daoura Homestead Community Land Trust 412 Maynard Avenue S, #201 Seatte WA B Renton Avenue S Condition Assessment May 17, john@homesteadct.org REGARDING Assessment Repot Dear Mr. Daoura, RDH Buiding Sciences has competed a survey of the buiding enveope components instaed on the six muti-unit residentia buidings ocated at 5008 Renton Ave. S, Seatte WA The foowing report outines our findings and recommendations as they reate to the buiding enveope. The report is broken down into the foowing sections: Background information; Visua Observations: Cadding & WRB; Doors & Windows; Roofs; Decks; Recommendations. Photo 1: Overview S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 1 OF 12

2 BACKGROUND RDH Buiding Sciences has been retained by Homestead Community Land Trust (HCLT) to review the buiding enveope components instaed on six buidings in the Coumbia City area of Seatte. It was reported to us that the partiay deveoped property is currenty bank owned and HCLT is a potentia buyer. HCLT has engaged RDH as part of their due diigence process prior to making a purchase offer. A of the six buidings are comprised of simiar wood construction athough each is in a different stage of deveopment. Construction of the buidings was stopped in 2010 due to unknown circumstances. They have been unoccupied in the interim. With the assistance of a contractor, RDH inspected the current condition of the property on May 9. VISUAL OBSERVATIONS Genera The property is strewn with mutipe pies of construction and garbage debris both outside and inside the units (photo 2). The concrete driveways are incompete and ony adjacent to buidings that are cosest to competion. Birds have evidenty taken refuge in most of the units with missing interior finishes as indicated by arge amounts of droppings and a few bird carcasses. The carcasses are argey intact indicating that other rodents have not occupied the buidings. The buidings are secure against casua entry. Ground eve doorways have instaed ocking door handes, whie the upper doors are secured with romex cabes or other devices attached to the hande/deadbot cores. Garage doors are covered with OSB sheathing. Driveway Termination Photo 2: Property Grounds Showing Debris and Incompete Concrete Work. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 2 OF 12

3 Cadding & Weather Resistive Barrier (WRB) Fortunatey, a buidings were covered with an exterior cadding system prior to abandonment by the deveoper. The instaation of the cadding and WRB has provided sufficient protection during the time from construction unti now aowing for the buidings to remain in manageabe condition and void of significant weather reated damage. Each of the six buidings is primariy cad with the foowing exterior system (see photo 3): 7/16 OSB Sheathing HardieWrap Weather Resistive Barrier 5/16 HardiePane Fiber Reinforced Pane (FRP) Siding The sma unit deck was are an exception to the above system, they are cad with horizonta wood battens instaed on vertica furring strips atop the HardieWrap. The HardiePanes are mechanicay attached fush with the WRB with no drainage pane provided between the was and cadding. Meta Z-fashing is instaed at the horizonta joints of each pane; however the WRB does not overap the vertica eg of the fashing and does not provide a drainage path for water that may penetrate behind the cadding. Four of the buidings do not have wa insuation or interior finishes instaed which provided easy access to the backside of the OSB sheathing for inspection. Isoated damage to the OSB sheathing was ony noted in a few ocations. Many of the exterior panes contain damaged corners in the vicinity of fasteners indicating over driven fasteners or a missed hammer swing (photo 4). This condition may be due to a hurried instaation of the panes as the property was being abandoned. Photo 3: Removed FRP Showing Fush Instaation of Panes over WRB. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 3 OF 12

4 Photo 4: Typica FRP Damaged Corner. Windows & Doors The doube pane, viny framed, fanged windows are manufactured by ViewPoint Windows & Doors. The sizing of the windows varies from 2 W x 2 H to 8 W x 7.5 H. The arger windows extend down to the foor substrate and defect significanty at the center muion intersection (photo 5). The water and structura resistance ratings are not provided by abeing on the units and are unknown to the author. The window assembies appear to be in good condition outside of a coupe isoated issues. One insuating gass unit (IGU) is hoding water between the two panes and wi require repacement (photo 6). In addition, the ower IGUs do not a contain etchings indicating a safety gass rating. The rating is required for a IGUs instaed beow 18. Photo 5: Large Window Extending to Foor Sheathing. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 4 OF 12

5 Retained Water in IGU No Back-Dam Ange Photo 6: Water Fied IGU; Water Stains on Foor Sheathing. No si pans have been instaed beneath the windows and the rough opening fashings vary between buiding paper, strips of Moiststop, and Grace Vycor. The windows are not tied to the WRB with fashing membrane atop the fanges or seaant behind the fanges (photo 7). The drip fashing instaed the window heads does not incorporate end dams. The OSB fooring substrate adjacent to mutipe foor eve windows shows signs of prior water intrusion in the form of sweing and deaminating strands (photo 6). It is uncear when this damage occurred and may be reated to construction practices. Framing members at the jambs and sis did not show signs of water infitration. Damaged WRB Photo 7: Window Fanges Not Integrated into WRB. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 5 OF 12

6 The doors instaed on the property are generay in good condition aso. As with the windows, the buiding paper has not been tied into the door frames. Roofs The pitched roofs are covered with composite shinges and fet underayment (photo 8). The shinge manufacturer and fet grade are unknown. The genera condition of the shinges and fashing materias is good with ony a few missing shinges in random ocations. A pitched roofs are constructed with soffit, gabe, and ridge vents. No attic insuation is present in the unfinished units due to the absence of a gypsum id. The missing ceiing panes aowed a fu review of the roof sheathing. No damages to the OSB sheathing were noted during the visua review. One of the finished units contained a stain and deaminating joint tape indicating a previous eak (photo 9). Drainage for the pitched roofs is provided by gutters and downspouts. In addition to the soped roofs over the main buiding, each of the units contains a cantievered bump-out window detai that is covered by a sma fat roof section (photo 10). These fat roofs are covered with a granue surfaced roed membrane. The sma fat roofs are soped to one side with no gutters instaed. Water fowing from the roof surface is aowed to pour freey off to one side. Photo 8: Overview of Typica Pitched Roof Condition S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 6 OF 12

7 Photo 9: Ceiing Water Stain in Finished Unit. Missing Gutter Photo 10: Typica Fat Roof over Bump Out. Unit Decks Unit deck waterproofing has been argey ignored even on the units that are near competion. The east finished units do not contain any waterproofing components atop the pywood sheathing or at best a mechanicay attached (fasteners exposed) fet sheet (photos 11 & 12). The two buidings that are cosest to competion contain a white, 60-mi singe-py materia instaed over the pywood; however the edges of the membrane have been poory terminated. Both conditions resut in deck sheathing that wi require repacement. Fortunatey, the deck framing members are comprised of treated umber and wi ikey not require repacement (see photo 13). S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 7 OF 12

8 Photo 11: Typica Unit Decks. Photo 12: Exposed Deck Sheathing with Partiay Attached Fet Sheet. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 8 OF 12

9 Photo 13: Treated Deck Framing. DISCUSSION & RECOMMENDATIONS The genera condition of the buiding wood framing and sheathing members is good. The instaed enveope components have protected the buidings sufficienty to continue with construction requiring minima remediation due to weather reated damages. Foowing a ceanup of the property to remove the garbage, construction debris, and bird reated issues, targeted repairs to the items noted in the previous sections can be undertaken. Repair of the noted items without further work outside of interior finishes wi achieve a minimay performing structure. These repair items incude: Repacement of HardiePanes with broken corners; Repacement of water fied IGU; Rebuiding of entryway at two story units: Ground foor door repacement; Investigation/repair of ceiing water stain(s) in finished unit; Remova/repacement of unit deck pywood sheathing; Target roof repairs of missing or damaged shinges; A minimay performing buiding wi ikey require reguar maintenance over the ifetime of the structures to avoid weather reated damages. It is aso unknown how the system wi perform once occupied due to changes in therma and moisture oading of the interiors. For these reasons RDH highy recommends the foowing changes to be undertaken to achieve a buiding enveope that wi propery manage water and prevent future interior infitration. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 9 OF 12

10 Exterior Wa Assembies The existing system does not incorporate a water management strategy. Moisture that gets beyond the fiber cement panes wi damage the structure through fastener penetrations or passage behind window fanges or door frames. RDH highy recommends converting the cadding system to a rain screen type assemby that wi aow for drainage of incidenta moisture behind the panes. The air space wi aso aow for convective drying of the assemby shoud excessive moisture enter. The conversion process wi require the foowing genera steps: 1. Remove / ega dispose of or recyce existing FRP and trim; 2. Repair WRB where needed: a. Tears / fastener penetrations; b. Overy weathered areas; 3. Integrate through-wa fashing: a. Remove horizonta Z-meta fashing at joints, egay dispose of or recyce; b. Cut existing WRB at fashing ocations; c. Tuck in new strip of WRB behind upper fap and over ower membrane to maintain weather apping; d. Insta new Z-meta behind upper fap of WRB with sufficient depth to accommodate added thickness of furring strips; 4. Re-detai window/door rough openings: a. See Windows and Doors for detais; 5. Insta vertica furring strips; 6. Attach new FRP over furring strips in accordance with manufacturer s instructions; 7. Insta new wood trim: a. Appy seaant at transitions where needed; 8. Paint or stain as needed. As outined above, the change of cadding system wi require remova of the existing panes and repair of the WRB materia where needed. Removing the existing panes wi ikey resut in damage to the fiber cement rendering the panes unusabe for re-instaation. However, the rain screen system can be instaed using simiar components to retain the buiding s current appearance. Windows & Doors In addition to the changes to the cadding system design, RDH highy recommends incorporating changes to the window & door rough opening detaiing. A window and door openings shoud have a si pan instaed and proper integration of the WRB into the pans. In addition, the openings shoud be propery detaied with si pre-strips and jamb/head fashings. To accompish changes to the rough opening detaiing, remova of the windows and doors wi be required. We woud anticipate 1-3% of the removed windows may be damaged in the process which woud require repacement; however a majority of the windows can be reinstaed foowing the additiona detaiing. That said we do not know the performance rating of the windows or the design requirements of the property. Water penetration testing shoud be conducted prior to re-instaation to confirm compiance with specifications and minima performance standards. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 10 OF 12

11 The genera steps required to compete the rough opening changes are outined beow: Roofs 1. Compete steps 1 & 2 in the Wa Assemby section above 2. Carefuy remove windows & store in safe ocation for repacement a. Cut WRB around window fanges prior to remova b. Pu fasteners remove window from opening c. Remove WRB from rough opening to cuts made in step-a above; d. Legay dispose of or recyce components. 3. Insta pre-strips and si pan: a. Attach pre-strip over WRB beneath si; b. Attach back dam ange on si; c. Tie-in pre-strip to back dam ange using foi faced sef-adhered membrane; d. Insta jam and head fashings behind WRB 4. Re-insta windows; a. Use shims at window si; b. Set jamb and head fanges into seaant; c. Sea back dam ange to inside of window frame; d. Tie window jamb and head fanges to WRB using WRB Tape; e. Insta meta head and si drip fashing; i. Set fashing into seaant; ii. Tie vertica eg of head fashing to WRB with WRB Tape. As stated earier the pitched roofs are in good condition and wi require minima repair and no design changes to achieve a high standard of performance. RDH does recommend instaing gutters at a fat roof areas. The downspouts from the newy instaed gutters can be easiy integrated into the existing system. Unit Decks The unit deck design can remain intact; however a decks wi ikey require sheathing repacement due to water damage. Any existing waterproofing shoud be removed to aow for inspection of the sheathing and framing components. Once repairs have been competed, RDH recommends a iquid appied eastomeric coating rather than the membrane currenty instaed on a few of the decks. The horizonta wa battens instaed around the decks are weathered and shoud be refinished or repaced as needed. Deck rais instaed on two of the buidings wi aso require changes to the connection detaiing to ensure resistance against water entry. The detaiing can be easiy addressed with the instaation of the eastomeric coating. CLOSING We appreciate the opportunity to assist you in the due diigence process prior to your purchase of the above property. The genera steps outined in our recommendation section are incuded for iustrative purposes ony; they do not incude a steps necessary to compete the tasks. S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 11 OF 12

12 Pease contact our office to discuss our recommendations in more detai or to assist with providing detais or product recommendations for impementation of the system changes outined. Yours truy, RDH Buiding Sciences Inc. Jeremy T. DeWitt P.E. Senior Project Engineer S:\B Renton Avenue S\B Condition Assessment\Report\B7482_ JTD LTR Assessment Repot.doc PAGE 12 OF 12