9.1 - 4113 Guadalupe St - Existing Building Structural Assessment Letter — original pdf

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September 15, 2026 To: Julie Briggs EFP 4113 Guadalupe LLC Aus&n, Texas julieermisbriggs@yahoo.com cc: Kris&n Schieffer, RA, LEED AP – ALIGN Aus&n Architects kris&n@alignaus&narchitects.com From: Nicholas Rohr, P.E., S.E. Managing Principal – Anderson Rohr Engineers, LLC Phone: 720-687-3730 Email: rohr@andersonrohr.com Structural Assessment Le(cid:23)er – Exis(cid:28)ng Building Project: 4113 Guadalupe Renova&on (ARE Project No. 26-060-ALA) Site Address: 4113 Guadalupe St, Aus&n, TX 78751 Site Visit Date: September 10, 2026 ARE A(cid:25)endee: Nicholas Rohr, P.E., S.E. Reference: ALIGN Aus&n Architects Preliminary Demoli&on Exhibit dated August 14, 2026 Introduc(cid:28)on On September 10, 2026, Nicholas Rohr, P.E., S.E. of Anderson Rohr Engineers, LLC (ARE) visited 4113 Guadalupe St to perform a visual structural assessment of the exis&ng building in support of the proposed renova&on. The General Contractor had removed finishes at the loca&ons shown on the ALIGN Aus&n Architects Preliminary Demoli&on Exhibit dated August 14, 2026, and the exposed structure at those loca&ons was observed and measured. The findings below are based on the condi&ons that were accessible on the date of the visit. Condi&ons that remained concealed by finishes, flooring, or the roof deck were not observable and are not included in this assessment except where noted as an&cipated. Only visual observa&ons were made; no material tes&ng, destruc&ve inves&ga&on, or geotechnical inves&ga&on was performed. Building Descrip(cid:28)on The exis&ng building is a single-story wood-framed commercial retail building with a brick front facade at Guadalupe Street. The building is approximately 50 feet deep by 25 feet wide, with adjacent buildings on each side. The exis&ng structure appears to be on an independent founda&on, separate from the adjacent buildings. The gap between the exterior north wall and the adjacent building to the north is approximately 21 inches. A masonry wall of the adjacent building is located along the south side. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 1 The primary structure consists of the following, as observed: • Founda&on: Timber piles embedded in the ground suppor&ng a 4x6 pressure-treated &mber beam at the perimeter. No concrete support was found at the &mber piles. The spacing of the piles could not be verified. • Floor: 2x6 floor joists at 24 inches on center bearing on the 4x6 &mber beam, with wood decking over. Joist spans could not be verified. • Walls: Load-bearing walls of 2x4 studs at 24 inches on center running the length of the building. The exterior finish on the side walls is wood paneling. The front wall behind the brick facade is non-load-bearing. • Roof: 2x4 ceiling joists and raHers at 24 inches on center, with flat 1x members perpendicular to the roof framing and wood decking over the flat members. The roof is approximately 11 feet above the finished floor; this dimension varies because of the sinking of the floor. • Lateral system: No shear wall components were found in the building. Figure 1. Exis(cid:5)ng front facade at Guadalupe Street – brick facade with storefront; the facade appears to bear on a concrete founda(cid:5)on. Figure 2. Rear of the exis(cid:5)ng structure – wood-framed building with paneled siding, set between adjacent buildings on each side. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 2 Figure 3. Gap between the exis(cid:5)ng 2x4 north bearing wall and the adjacent building to the north – approximately 21 inches. Water drains through this gap and toward the building. Figure 4. Exterior wall of the adjacent building to the south, viewed from the gap between the buildings. Observed Condi(cid:28)ons Founda(cid:28)on and Floor Framing The floor joists bear on the 4x6 pressure-treated &mber beam, which spans between &mber piles embedded directly in the ground. No concrete foo&ngs or piers were found. The floor has a depression of approximately 2 to 4 inches, with the low point near the middle of the floor. The floor level varies across the building. Signs of water damage and water infiltra&on were observed underneath the building, including water marks on the exposed pile shown in Figure 6. Much of the deteriora&on of the wood is likely due to water damage. Severe deteriora&on of the floor joists was observed near the perimeter where the floor was exposed. Many of the joists observed were deteriorated. Further deteriora&on that is not visible is likely beneath the exis&ng wood decking. SpliIng of the wood was also observed, which may result from non-preserva&ve-treated wood being exposed to the elements. The 4x6 perimeter beam appears to be pressure treated and appears to be in be(cid:25)er condi&on. The floor depression and the differen&al movement behind the front wall are likely the result of water infiltra&on at the &mber pile founda&ons. Water currently drains into the gaps between the exis&ng building and the adjacent buildings on the north and south sides, and likely under the building. This allows the soils at the &mber piles to soHen and the main bearing walls to sink. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 3 Figure 5. Exis(cid:5)ng 4x6 pressure-treated (cid:5)mber beam suppor(cid:5)ng the floor joists. Figure 6. Timber pile founda(cid:5)on suppor(cid:5)ng the 4x6 (cid:5)mber beam – no concrete support was found. Figure 7. Deteriorated 2x6 floor joists at 24 inches on center bearing on the (cid:5)mber beam and pile founda(cid:5)on. Load-Bearing Walls and Siding Figure 8. Approximate varia(cid:5)on in floor height at the sinking floor – the markup shows the distance from the floor to the horizontal wall member, approximately 8 inches near the middle of the building and approximately 5 inches toward the end of the wall. The difference is the approximate floor depression of 2 to 4 inches. The bo(cid:25)om sill plates and the bases of the 2x4 studs are deteriorated along the exposed por&ons of the north and south bearing walls. Splits were observed at the base of the wall studs. The wood paneling siding on the side walls has large gaps that allow moisture to infiltrate the wall, which has led to the deteriora&on of the wood. SpliIng of the wall studs was also observed at loca&ons that are not shown in the photographs. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 4 Figure 9. Bo2om of the exis(cid:5)ng 2x4 bearing wall with floor joists bearing, adjacent to the neighboring building wall. The sill and stud bases are deteriorated. Figure 10. South wall – deteriorated wood wall construc(cid:5)on. Splits and sec(cid:5)on loss at the base of the 2x4 studs. Figure 11. South wall base deteriora(cid:5)on at the adjacent building – moisture infiltra(cid:5)on through the gaps in the siding. Figure 12. North wall – interior deteriora(cid:5)on and water damage at the sill and stud bases. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 5 Front Facade The following was observed at the front of the building: • The front facade appears to bear on a concrete founda&on and appears rela&vely stable. The brick did not show large cracks that would indicate significant movement. • The front facade appears to show minor movement, resul&ng in the minor stair-stepping of the brick mortar joints at the facade return shown in Figure 14. • Gaps were observed in the brick at the base of the facade where the brick meets the concrete founda&on (Figure 15), and the sidewalk has separated from the front founda&on (Figure 16). • There is a crack in the front wall founda&on at the doorway (Figure 16), indica&ng that the front concrete founda&on is not completely stable. The magnitude of movement appears to be much less severe than in the &mber-pile-supported por&ons of the building (the north and south walls). • The front wall is non-load-bearing. The north and south walls, which run perpendicular to the front wall behind it, are load-bearing. These walls are supported on &mber piles and appear to be showing the most movement. • The most severe movement is near the middle of the building. As the north and south walls approach the front wall, the movement appears to be more minor, indica&ng that the middle of the building is sinking the most. There may be a low point in grade near the middle of the building where water cannot escape. Figure 13. Exis(cid:5)ng front facade – storefront and brick parapet. The historic facade is to remain. Figure 14. Stair-stepped separa(cid:5)on at the brick mortar joints at the facade return – minor; possible indica(cid:5)on of soil movement. No large cracks were observed in the facade. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 6 Figure 15. Gaps in the brick at the base of the facade where the brick meets the concrete founda(cid:5)on. Figure 16. Crack in the front wall founda(cid:5)on at the doorway, and separa(cid:5)on between the sidewalk and the front founda(cid:5)on. Roof Framing The roof structure did not appear deteriorated where visible. The 2x4 ceiling joists and raHers, flat 1x members, and wood decking were observed at the loca&on where the dropped ceiling was removed. Findings The exis&ng wood structure at the floor level (&mber piles, 4x6 &mber beam, 2x6 floor joists, sill plates, and the bases of the 2x4 studs) is deteriorated and will need to be replaced or supplemented with new structure to bring the building into code compliance. The following is noted: • The maximum span for a 2x6 floor joist at 24 inches on center under the current IBC floor loads (100 psf mercan&le live load) is approximately 5 feet 0 inches. The exis&ng joist spans could not be verified, but the floor is sinking and many of the observed joists are deteriorated. • The exis&ng 2x4 wall studs have sufficient capacity for the roof loads; however, the deteriorated stud bases and sill plates must be repaired to restore the original support. • No shear wall components were found. The building has no defined lateral system. • Signs of water infiltra&on and water damage were observed beneath the building. Much of the deteriora&on of the wood is likely due to water damage. • The &mber pile founda&ons are embedded directly in soil that is subject to water infiltra&on and are experiencing differen&al se(cid:25)lement. • The exis&ng siding does not keep water out of the walls. • The roof framing did not appear deteriorated where visible. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 7 Recommenda(cid:28)ons 1. Redirect Site Drainage Away from the Building The new construc&on should redirect all water runoff away from the building and prevent water from draining into the gaps between the exis&ng building and the adjacent buildings on the north and south sides. Without correc&ng the drainage, any founda&on repair remains at risk of con&nued movement. 2. Replace the Timber Pile Founda(cid:28)ons ARE recommends replacing the &mber pile founda&ons with concrete founda&ons during construc&on to provide be(cid:25)er bearing and reduce differen&al se(cid:25)lement. A geotechnical engineer should be retained to evaluate the on-site soils and determine the poten&al movement of the soils for shallow founda&ons. Alterna&vely, driven piles or helical piles may be installed to extend the founda&ons below the ac&ve zone of soil movement. For pricing, the General Contractor should price the following op&ons for the perimeter founda&on: • Op&on 1 – New con&nuous concrete grade beam, 12 inches wide by 24 inches deep, along the perimeter bearing walls. • Op&on 2 – Keep the exis&ng 4x6 perimeter &mber beam and install new piles at 5 feet 6 inches on center along the beam line, approximately 50 feet long total. • Op&on 3 – Remove the exis&ng 4x6 perimeter beam and install new piles spaced further apart with a new rim beam designed to span between them. 3. Replace the Floor Framing ARE recommends replacing the exis&ng 2x6 floor joists with 2x10 floor joists at 16 inches on center spanning 8 feet 6 inches maximum, in three bays across the width of the building. The exis&ng 2x6 floor joists may be removed once replaced. Install new interior girders of (4) 2x12 at the third points of the floor, with founda&on supports (spread foo&ngs or piles) at 9 feet 0 inches on center. With the girders bearing at each end of the building, this is five interior supports plus one at each end – seven supports per girder line over the approximate 50-foot building length. As an alterna&ve to a framed floor, the geotechnical engineer may provide recommenda&ons for soil remedia&on and compac&on to replace the exis&ng floor with a 4-inch slab on grade. 4. Repair the Bearing Walls and Add Wall Sheathing The exis&ng 2x4 wall studs should be replaced or lapped at the base, with new sill plates, to restore the original support. ARE recommends replacing the siding with plywood sheathing along the full length of the walls to provide lateral rigidity and a shear wall system, and reinstalling the exterior siding to waterproof the building. Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 8 5. Construc(cid:28)on Approach – Two Op(cid:28)ons to be Priced Because of the historical nature of the building, the front facade may not be replaced. The front wall behind the facade is non-load-bearing. Two approaches are available: • Op&on A – Shore the front facade and replace the structure behind it. The General Contractor shores the front facade during construc&on, and the three walls behind the facade are removed and replaced with a new structure on new founda&ons. • Op&on B – Shore the en&re building and reinforce in place. The building is shored during construc&on and the founda&ons, floor framing, wall bases, and sheathing are repaired in place as described above. Op&on A may be more cost effec&ve than shoring the en&re building and reinforcing in place. ARE recommends the General Contractor price both op&ons. Limita(cid:28)ons This le(cid:25)er is based solely on visual observa&ons made by ARE during the September 10, 2026 site visit at the loca&ons exposed by the General Contractor. No destruc&ve inves&ga&on, material tes&ng, or geotechnical inves&ga&on was performed. Concealed framing, pile spacing, joist spans, and soil condi&ons were not verified. Further deteriora&on beyond what was observed should be an&cipated once the remaining finishes and flooring are removed. Final design of the founda&ons, floor framing, wall repairs, and shoring will be provided under a separate agreement once the construc&on approach is selected, and founda&on design will be coordinated with the geotechnical engineer. Please contact our office with any ques&ons regarding this le(cid:25)er. Sincerely, Nicholas Rohr, P.E., S.E. Managing Principal Anderson Rohr Engineers, LLC Anderson Rohr Engineers, LLC – Structural Assessment Le(cid:25)er P a g e | 9 9/15/2026