2015-01445 - add/remodel/repair - Laserfiche WebLink

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1�tU i�Svt�liAtll.ClUf YU�Rl�i!�lJl�it; ' struaurel engineerz ' Observations and Comments In general,the deck structure was observed to be in good condition,with a few minor items we recommend to be addressed, as well as the support of the chimney, which we review in more detail below. No failed members were observed, and while deflection was visible in a couple areas(discussed later), the deflections do not appear to exceed code-suggested limits, and are not judge to be excessive in our opinion. A few minor items of note were observed that are not directly related to the chimney: 1. There are a few joist hangers without proper nailing to the ledger board. 2. There are no visible connections from the top of each post to the deck framing. 3. The post spacing at the southwest edge of the deck appears irregular,and is reported to be a result of underground tanks in the vicinity. Chimney and supporting deck framing: 4. The masonry veneer on the fireplacQ and chimney is an adhered, cultured stone that is supported by its back-up structure rather than at its bottom edge.Some comments regarding this construction: a. While it is not typical to support full-thickness veneer or structural masonry on wood framing, and there are code provisions against such configurations, the support of an adhered veneer is somewhat different. An adhered veneer,which by definition has its weight supported by adhesion to a back-up structure, often relies on wood framing for support. b. Where wood framing serves as a backup wall to support an adhered veneer,the veneer is more sensitive to minor deflections than a more flexible cladding such as siding. As such, it is most typical, and preferred to bear directly on a concrete or masonry foundation wall. However, where wood framing members are adequately sized both to provide sufficient strength and limit deflection, adhered masonry veneer can perform appropriately. 5. There is a minor separation between the adhered masonry veneer and the house wal�, indicative of very slight deflection of the deck joists bearing the weight of the fireplace and veneer. This separation is less than 1/8", and is not considered excessive. 6. Existing installed joist hangers supporting the doubled 2x12 joists are "Simpson LUS210-2Z" attached to the treated 2x12 ledger attached to the house. 7. There are existing windows framed into the house wall below the deck and chimney.There appears to be slight, but visible deflection of the headers, with no other signs of distress. The windows are reportedly operational, and the deflection is not considered excessive(Given that the framing is covered,no further evaluation was sought). Analysis Based on field observation and measurements, I reviewed the deck structure and analyzed the existing members based on code-prescribed loading. Per the Minnesota State Building Code 2015, I considered live and snow loads of 40 and 35 pounds per square foot (psf), respectively. I used the thickness of the adhered veneer and its typical weight, and estimated the weight of framing and fireplace insert.We assumed the that weight of the veneered fireplace surround as well as a portion of the chimney above is bearing on the deck framing, based on description from the contractor as well as industry-standard building techniques.The following summarizes our findings: • The existing (2) 2x12 @ 16" OC are adequate to support the loads imposed, and under the design loads would be expected to perform without exceeding deflections as suggested by code. • The existing Simpson LUS210-2Z hangers are an appropriate selection for the imposed load, based on the manufacturer's product documentation. • The treated 2x12 ledger against the house is adequately sized. • The connection of the 2x12 ledger to the house appears to be undersized for the estimated dead loads in combination with code-prescribed live loads. Since the exact framing configuration cannot be discovered without removing finishes, and the weight of the chimney cannot be assumed to be completely supported by the house wall, we recommend supplementing or relieving this connection. • The rim beam at the outer edge of the deck is undersized for the estimated dead loads in combination with code- prescribed live loads. We recommend reinforcing this beam or installing additional posts to shorten the effective span of the existing beam. d355 Baysfue F�d-Reixni :3 of 5