I was asked to review an existing house basement (40 yrs old +/-) that has cracked full height vertically at the corners. I have never seen anything like it because they look like shrinkage cracks, but rather than occuring at the centre of the walls, or at some windows, they are in the corners...
Has anyone used expanding mortar for concrete demolition? I had an architect ask me about using it on a project & I'd never heard of it. His concern is noise and dust from jackhammers, not replacing explosives. I suspect that it's so expensive it's only used as a last resort when explosives...
I have an architect who wants a 40' clear span opening in a concrete wall of a residence. The wall is actually one side of a concrete box: there is a reinforced concrete deck on top of it that is an exterior patio. I have 4' of depth above the opening and plenty of wall beyond it at both ends...
I've got an owner who wants to put a 5th floor on a 115 year old 4 storey masonry load-bearing wall (4 wythes of brick) building. It has wood-framed floors & flat roof. He has a prospective tenant who wants to run a rooftop restaurant, mostly glass-enclosed. The building is only 28' wide, but...
I'm a structural guy who didn't mind soils in school 30 years ago but has mostly dealt with them since for foundation bearing. A project that I'm involved in has a problem that's not mine, but I am uncomfortably close to it. A house was torn down & a new one is being built 75' from the top of...
I'm a structural guy working on a 3 storey building design for someone who has built a couple of houses & knows everything. He has done his own hydronic heat & wants to do it again, & I want to use precast hollowcore floors with a topping for the tubing; the precast would form the finished...
Any suggestions for solving an existing undersized return? The supply is 12X20 and the return is 12X18, the HVAC unit sits on an exterior pad at grade. The return simply goes up the wall 10' (in an insulated, clad shaft) and into a ceiling plenum. The supply is ducted to each office. Supply...
I read an earlier thread in which Ron stated that he has used expanding foam adhesive to tie masonry veneer to its back-up when the original ties had failed. I have never heard of this before and had the same initial reaction as hokie66, but I am interested in learning more. I frequently deal...
I have a mechanical contractor insisting to me he can save an owner a ton of money because his system of adding a hot water coil into an air handler is far more efficient than a high efficiency gas furnace. I say it is physically impossible to be more efficient with a burner of the same...
I have recently designed 2 similar residential wood-framed canopies carried by 2 cantilevered steel beams. They are extensions of flat roofs out in front of the overhead doors on garages; the 2 beams carry wood joists. The first canopy was very soft & I had to design stiffening for the beams...
I am designing a grade beam on helical pier foundations to carry a 2 storey residential building on a site with 15' +/- of fill. I have designed concrete beams for lintels & suspended floors before and am looking at a similar design for strength to carry my loads but 2 pier contractors I have...
Does anyone have a good way to calculate the tension required on a 3/16" cable that is acting as part of a guard at a stair opening? The cables are 3 1/2" apart and run vertically from the 1st floor to the 2nd floor ceiling, passing through sleeves in the end of each tread & the second floor...
I recently designed a concrete foundation for a 350,000# hammer. It was a used hammer, & the owner supplied information based on the previous installation. Soil tests were done, & the soil is stiff clay with bedrock at about 75' depth. The foundation extends about 21' below grade, and is...
