enjoying a bit of foundation work on my house

[LCHIEN]

I'm on day 2 of foundation work.
For the last couple of years we've been seeing signs of settling on the 18 year old house. Cracks appearing between sheet rock sections. Splitting woodwork joints, doors that don't quite close right. Cracks in the ceramic tile grout.

had some guys come and measure the level and some peripheries of the house are down as much as 1.5 inches. A professional engineer's measurements agreed closely with the reps for the foundation companies.
fortunately only need piers around the periphery - but i do need 28 of them. Gonna cost about 2 european vacations.

Fortunately only four piers where there's concrete. They repair the concrete but not the brick porch stoop so i had to contract a brick man to remove, reclaim and then relay the brick stoop after they break up the concrete underneath to place piers. Another $850. (high quote 1350, low quote 750) He actually sawed the grout out, took the bricks away to clean and will bring them back.

This morning the yard looked like an attack of giant gophers. Mounds of dirt all over from the 28 holes. When i get back tonight the piers should be installed and driven, the floor level and concrete poured. They tell me the cracks should close up and door frames level out.

[pelligrini]

Been needing that done on my house too. I keep telling my wife not to caulk any of the sheetrock cracks. She filled one big one a couple summers ago, a really dry summer. That next wet winter made a bigger mess of that wall when the crack closed up quite a bit, causing lots of other little fractures as the gap was filled.

What system did you end up going with? Metal piers or those concrete cylinders?

[Kristofor]

How do they do foundations down there normally?

Obviously you don't need to go down several feet to get below the frost line, and it seems that basements are uncommon down there. Having never really thought about it, I assumed that they would still have a foundation below the slab/structure just not as deep...

Is that a silly northern assumption, or is that how it's done there but the soil just had some issue causing uneven settling?

[pelligrini]

Most of the construction around here is just an uninsulated concrete slab on grade. Usually a 4" slab with 24" grade beams around the perimeter and some interior beams 10-15' apart. Some areas and larger structures will put the grade beams on concrete piers drilled down to a stable strata. The majority of the houses don't have piers now.

In my area there is a whole lot of expansive soils, lots of clay. Even when bringing in a couple feet of select fill and putting the slab on it there will be some problems in several years down the road. Say a house settles just a 1/32" a year over time all that movement can add up. It can get much worse with improper site drainage too.

[cgallery]

Why do you have to add piers, why can't they use the existing piers and just add blocks to level the house?

[pelligrini]

I bet Loring's is like mine, just a slab, no piers.

[LCHIEN]

erik P is right, concrete slab only.
They are hydraulically driving those cylidrical concrete piers into the ground until they won't go any more ("point of refusal", aptly named) then they jack against that to push the beams in around the perimeter of the foundation under the house up.

my Chimney is two stories high, it had been pulling away from the house by about as much as an inch. They piered up under the chimney and the surrounding walls and I hear it went back flush against the house.

[cgallery]

Are there any new techniques/technologies being employed on new homes (last few years) in Texas where adding piers in the future wouldn't be necessary?

[pelligrini]

Not sure about new tech, but a lot of the high end homes we design incorporate drilled piers done by the structural engineer. We had one behemoth designed with carton forms underneath to protect from heaving too, basically a floating concrete slab on piers. The stuff we do isn't the norm though, 5000 sq ft and way on up residences, multi-story condos etc.

A lot of it boils down to cost and liability. Most jurisdictions require an engineered foundation now, but even then those may have problems years down the line. The limit on structural liability is 10 years. It's fairly unusual to see foundation problems before the first decade is up. A lot of the smaller production homes won't spend the extra money putting in piers.

The custom builders we work with pay a little more attention to foundations and structural. We always get fresh geotech done on a site for the structural engineers to work with.

There is some new tech being developed in repairs, like the system that's being used in Loring's case. Ram-Jack has a fairly new screw system too. I don't know a lot about the mud-jacking that's being done sometimes either.