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HomeMy WebLinkAbout2022-03-03 Diamond Bar Village Cannon Review - ESE Response.pdf Plan Check Comments Structural Response • Building A: o Unit 20 wing wall by entry – there is small hole that needs a stucco patch. ESE: Note added in 6/SK-2 to address the issue. See Du Mont drawing and response for the repair detail. o Unit 15 wing wall by entry – there is an existing investigation patch that needs to receive a stucco cover. ESE: Note added in 6/SK-2 to address the issue. See Du Mont drawing and response for the repair detail. • Building B: o Unit 6 end roof beam over wall – beam is badly decayed and should be replaced. ESE: See added detail 4/SK-3. A 4x8 beam is added. o Unit 7 end roof beam over wall – beam is badly decayed and should be replaced. ESE: A 4x8 beam is added in 1/SK-3. o Unit 8 end roof beam over wall – beam is badly decayed and should be replaced. ESE: A 4x8 beam is added in 2/SK-3. • Building C: o Roof step between Units 8 and 9 – beams are badly decayed and should be replaced. ESE: It is our opinion that the existing beams at the step still have the capacity to resist the roof load after repaired with epoxy and termite/fungi treatment. • Building D: o Unit 11 end roof beam over wall – beam is badly decayed and should be replaced. ESE: Detail 8/SK-7 is added to replace the end beam. • Buildings E, F, G, and H: o No issues. • Building I: o Unit 10 roof over deck adjacent to wing wall – roof deck needs replacement. ESE: Roof sheathing replacing note is added in detail 5/SK-12. • Buildings J and K: o No Issues. Roof Plans: I examined the roof conditions of buildings C, D, G, and J. As noted in my prior report, I observed: • The stucco caps at the parapets and wing walls are cracked and spalled at most locations such that they allow rain intrusion into the tops of the walls. • One noted condition was of a loose clay roof tile that had slid down over the top of the adjacent tile below (at one of the building C mansards). It is unknown how common this condition is. • The interior side on some of the roof parapet walls have torn finishes or are entirely missing finishes which provides a path for water absorption into the walls. Wall Flashing Caps: The Englekirk plans indicated repairs to most of the walls that extend up past the roof (and parapet walls) that were originally finished with stucco over the top of the wall. I observed that many of the metal wall cap flashings that were added over time were in poor condition and should be replaced. I recommend that all the flat stucco at the top of the walls (and parapets) at all buildings have new integrated cap flashings that are appropriately attached, integrated with the wall interior and exterior finishes, and sloped to drain. ESE: The as-built metal wall cap flashings may not be as per the current standard of new construction, but it is our opinion that they may still function well to prevent the water intrusion from the top of the wall. For other locations where spalled stucco occurs, see Du Mont drawing and response for repair detail. Parapet Wall Finishes: The interior, non-stucco, wall finishes were not addressed by Englekirk. I noted numerous locations where the inside face of the parapet walls finish was not stucco and the finish material used was integrated into the roofing system. In several observed locations, the material was torn or missing entirely. I recommend that the new parapet caps include a flashing system compatible with a future roofing and parapet wall finish system. ESE: The waterproofing deficiencies that will have immediate impact on structural integrity were identified on the sketches prepared by Englekirk. Typical Roof Details: I reviewed the Englekirk details shown on drawings SK-30 to SK-33 and offer the following: o SK-30: o Details 1 and 2: There is no mention of integrating flashing and building paper into the repairs. ESE: Note 6 in detail 1 and note 3 in detail 2 are added to address the issue. See Du Mont drawing and response for the repair detail. o SK-31: o Detail 1: o The fascia should be replaced with new pressure treated fascia. ESE: Note 2 is added. o No diameter is indicated for the Titen HD screws at the base plate. ESE: ½” diameter callout is added. o Detail 2: o All new wood should be pressure treated. ESE: Note 3 is added. o The wall framing below the beams in these locations are very likely to have rotted framing below. There should be a note regarding replacing all rotted wood with pressure treated wood. ESE: There are a few locations with holes in these walls still exposed from the previous inspection. The wall framing at these locations doesn’t appear to have essentially structural damage. More locations are identified in the sketches requesting exposure work for further inspection. More details are to be provided pending inspection at these locations. o SK-32: o Detail 1: o The edge distance between the 3x6 ledger and the screws indicated is very short and likely to split the wood. I suggest maintaining a minimum 4” dimension between the ends of the blocks and the connectors. ESE: The toe nail shown is just a typical application. The wood members involved are new and the splitting concern is minor. o Most likely there is blocking between the roof joists atop the wall top plate and roof sheathing. That blocking would provide a better opportunity for connectors. ESE: The existing drawing shows there is only a partial height blocking between the roof sheathing and wall sheathing with a rough size of 2x4. It is difficult to apply connectors to that blocking because of the roof slope. See below. o See the attached optional support connection for consideration. o Detail 2: o This detail’s bolts at two-foot centers may transfer load into the added 4x10 beam, but there may not be enough bolts at the ends to transfer enough shear back into the original beam for transfer into the wall (the added beam has no shear transfer connectors to bypass the original beam). My observation was that most wood decay occurred at the ends of the beams and that the original beams may not have enough remaining shear capacity to transfer loads to their support framing in the walls. ESE: The existing girder is 6x14 D.F. Dense #1. With DL of 25 psf and LL of 20 psf applied on the beam, the shear stress demand capacity ratio at the ends is only 0.06. It is our opinion that the conditions of all the 6x14 girders are good enough to have much more than 6% shear capacity remaining at the ends. o SK-33 o Detail 1: o No comments. o Detail 2: o No diameter is provided for the Titen HD anchors. ESE: ½” diameter callout is added.