Concrete Foundation Contractor Needed

[cwrm4]

I'm looking for recommendations on a concrete contractor to excavate, fill, compact, form and pour a slab for a garage apartment in the Heights. (I've already prepared the drawings and have the building permit in hand).

The driveway is down the side of the house, and very narrow, so will likely have to use a pumper truck (or lots of guys with wheelbarrows). I'm an engineer, and worked in commerical construction a bit in DC. I'm fully aware of the shortcuts many concrete guys will take on residential construction, so I'm looking for someone competent and honest for this job, since it is my house!

[ijaxon]

pm me

[chuckdiesal]

I'm looking for recommendations on a concrete contractor to excavate, fill, compact, form and pour a slab for a garage apartment in the Heights. (I've already prepared the drawings and have the building permit in hand).

The driveway is down the side of the house, and very narrow, so will likely have to use a pumper truck (or lots of guys with wheelbarrows). I'm an engineer, and worked in commerical construction a bit in DC. I'm fully aware of the shortcuts many concrete guys will take on residential construction, so I'm looking for someone competent and honest for this job, since it is my house!

Did you find someone?

[rigas]

i am a residential concrete contractor, and the heights is my generall area of work.

i assume by this time you have found a contractor but if not feel free to contact me.

Rigas concrete construction, llc

281-955-0537

chris

[Specwriter]

I'm an engineer, and worked in commerical construction a bit in DC. I'm fully aware of the shortcuts many concrete guys will take on residential construction, so I'm looking for someone competent and honest for this job, since it is my house!

Since you are an engineer your are probably familiar with some of the challenges the local soils can give. You probably had soils tests done prior to your slab design. I know there are good contractors out there who know what it means to build a true floating slab in Houston but they are probably not in the majority. Find one who will follow the design and be prepared to pay for it.

Here are two good stories about residential concrete work done in the area.

My former (and late) neighbor built a house near Hobby Airport in 1959. He was a mechanical engineer but understood and appreciated the necessity of designing for the expanisve soils in the area. He had built an approximately 2500 square foot brick veneer house with a detached three-car garage and mother-in-law apartment. Thirty-eight piers were sunk to support the slab of the house and garage/apartment. The house had terrazzo floors as well. When I was last in the house in the late 90's (almost 40 years after it was built) there were no signs of slab movement at all - no cracks in bricks or even the mortar and the terrazzo floors appeared as new. By the way, being a mechanical engineer he also had a hell of a water-cooled air conditioning system for the house. The owner had to replace only one pump and one compressor in the entire 41 years that he lived there.

The second story involves a driveway installed by my current neighbor. I will mention first that the 1959 house had no special measures taken for its concrete drive and it looked like a hammered Graham cracker. Across the street from my present house the driveway looked much as mine does now: cracked and heaved in places either by tree roots or differential settling. My neighbor's brother is a residential and small commercial contractor.

The neighbor had a concrete crew recommended by this contractor brother replace the 80-foot long, 16-foot wide drive way about five years ago. before they set the form work the existing soil was excavated about 12 inches. The soil below that was "limed" to stabilize it and select fill was placed to bring the base to the correct elevation. Then the five-inch thick concrete driveway was poured using #3 (3/8 inch diameter) rebar for reinforcement and not the 6-gage welded wire fabric used in most spec flatwork.

My neigbor has a fairly large boat (twin I/O engines and pulled by his 1-ton turbo pickup truck) which he sometimes parks in the driveway on Friday aftenoons as he loads it up for weekend use. This rig is heavy. After five years the driveway still looks great. So, in 500 words or less, preparation is key. Good luck.

[rigas]

specwriter

intersting stories. the biggest issues i run into as a residential concrete contractor has absolutely nothing to do with site conditions or expansive soils but more to do with the builder/home owners pocket book. the diveway you describe would be WAY out of most peoples budget and a bit of overkill for the normal uses of a driveway. (not sure why he only used #3 rebar though, he should have spent the $300 to go with #4 in the 5" thick slab) i understand his reasons, i have a large boat myself. i would not recomend anything similar for the average home owner, there is just no need for all of that for normal everyday use.

the only thing i need to correct is the reference to welded wire mesh, 1st it is not the norm (the norm these days on new construction has no reinforcement at all except on the "city side" of your property line) 2nd, welded wire mesh can be as good or better then #3 rebar. it all depends on the aplication in which it is used.

[Specwriter]

specwriter

intersting stories. the biggest issues i run into as a residential concrete contractor has absolutely nothing to do with site conditions or expansive soils but more to do with the builder/home owners pocket book. the diveway you describe would be WAY out of most peoples budget and a bit of overkill for the normal uses of a driveway. (not sure why he only used #3 rebar though, he should have spent the $300 to go with #4 in the 5" thick slab) i understand his reasons, i have a large boat myself. i would not recomend anything similar for the average home owner, there is just no need for all of that for normal everyday use.

the only thing i need to correct is the reference to welded wire mesh, 1st it is not the norm (the norm these days on new construction has no reinforcement at all except on the "city side" of your property line) 2nd, welded wire mesh can be as good or better then #3 rebar. it all depends on the aplication in which it is used.

Yes the driveway was "over the top." I'm sure my neighbor got a good deal though from his brother's concrete contractor. I agree that WWM can be used to do a proper job for flatwork. Remember its function is as much to conduct the heat of the setting reaction away from the center of the mass of concrete as it is to reinforce the concrete. It certainly helps if the mesh is not mashed down to the bottom by folks stepping on it. Actually, as you know, it needs to be pulled into position as the concrete is poured. There is really no way a person can step through the 6-inch by 6-inch squares while trying to place the concrete.

I think the really important thing (and again, this increases cost and is not really the responsibility of the concrete contractor) is preparing the base properly for the concrete that will be poured on top of it. Certainly the only way soil stabilization can be justified for driveways, from an economic standpoint for the average homeowner, is if he or she plans to remain at that property for many years and plans to drive heavy vehicles over it . For building slabs it is vitally important to prepare the base properly and to use a really good vapor barrier.

My driveway should be replaced. It would certainly help the resale value of the house but, I would never recover the total cost if I were to do as my neighbor did with his driveway. I hope to relocate within five to ten years.

Rigas, thanks for the practical perspective. One more thing I should mention (also in agreement with your statement) is that it doesn't appear that the expansive soils do as much damage to driveways and sidewalks as tree roots do. If somebody has knowledge about whether tree roots can be "trimmed" like a major branch prior to having a new driveway installed let me know.

[cwrm4]

For what it's worth, I excavated two feet, "limed it", and then had it built it back up with select fill, compacting in 6" lifts. I poured a 5" slab with #4 rebar over 16" wide x 30" deep perimeter beams + 12" wide x 30" deep interior beams (#5 steel in the beams). I almost did 12 x 24 beams over drilled piers, but you have to draw a line somewhere.

I also spec'd a 4000 psi mix and paid to have a testing guy onsite (and made sure the plant knew ahead of time that a testing guy would be there during the pour). I made sure the drivers knew that I was the only one who could approve adding water. Anyway, the mix tested to 4400 psi at 7 days. I may have spent a few thousand more than I needed to, but my slab isn't going anywhere anytime soon. I do plan to later put a car lift in the garage.

In the end, it was very clear to me that, had I not lorded over the concrete work, I wouldn't have gotten anything close to a properly prepped and poured slab. And I guess that is why nearly everyone I know with a new home on a slab in Houston complains constantly about "cracking and settling".

[Specwriter]

In the end, it was very clear to me that, had I not lorded over the concrete work, I wouldn't have gotten anything close to a properly prepped and poured slab. And I guess that is why nearly everyone I know with a new home on a slab in Houston complains constantly about "cracking and settling".

Good on you, cw. It's your house and your money and, even so, you see what you have to do to get what you want. It sounds like you did everything that could be done (and correctly). I hope that your new garage give you many years of great service and enhances the enjoyment of the projects you undertake in it. I always rationalize that the extra money I spent on something like a home improvement would have been blown on cigars and whiskey anyway. Better to put it into my house.

It does my obsessive-complusive heart good to know that somebody else cares about his "stuff" being nice and working well.

[cwrm4]

It does my obsessive-complusive heart good to know that somebody else cares about his "stuff" being nice and working well.

Thanks, we may be the only two out there! I'm amazed at how many people tell me "I can't believe you are spending that much on a garage"...and then they go climb in their brand new Range Rover (which will depreciate $25k in one year) and drive off.

By the way, the 28-day test came back at 5000 psi! I guess when the plant knows you are going to have it tested, they tend to err on the side of too strong.

[Specwriter]

By the way, the 28-day test came back at 5000 psi! I guess when the plant knows you are going to have it tested, they tend to err on the side of too strong.

Go get that car lift and enjoy.

[rigas]

Yes the driveway was "over the top." I'm sure my neighbor got a good deal though from his brother's concrete contractor. I agree that WWM can be used to do a proper job for flatwork. Remember its function is as much to conduct the heat of the setting reaction away from the center of the mass of concrete as it is to reinforce the concrete. It certainly helps if the mesh is not mashed down to the bottom by folks stepping on it. Actually, as you know, it needs to be pulled into position as the concrete is poured. There is really no way a person can step through the 6-inch by 6-inch squares while trying to place the concrete.

I think the really important thing (and again, this increases cost and is not really the responsibility of the concrete contractor) is preparing the base properly for the concrete that will be poured on top of it. Certainly the only way soil stabilization can be justified for driveways, from an economic standpoint for the average homeowner, is if he or she plans to remain at that property for many years and plans to drive heavy vehicles over it . For building slabs it is vitally important to prepare the base properly and to use a really good vapor barrier.

My driveway should be replaced. It would certainly help the resale value of the house but, I would never recover the total cost if I were to do as my neighbor did with his driveway. I hope to relocate within five to ten years.

Rigas, thanks for the practical perspective. One more thing I should mention (also in agreement with your statement) is that it doesn't appear that the expansive soils do as much damage to driveways and sidewalks as tree roots do. If somebody has knowledge about whether tree roots can be "trimmed" like a major branch prior to having a new driveway installed let me know.

i dont know where you got that WWM is placed to conduct heat from the core of anything. this statement is completly false. WWM is nothing more then reinforcement. there is no need to conduct heat AWAY if anything you want the heat of hydration to stay inside. the key is to keep the hydration going by keeping moisture involved. water curing, covering the slab area, curing compounds, are all made to keep the heat of hydration inside along with the water content.

i agree 1005 with your other statements just not this one. i have been an ACI, PTI, and ASCC memeber for years and have never heard of such a thing.

as for "pulling up the mesh", this all depends on what your plans for the mesh are. mesh is generally not ment for much strength but is very good for surface strength. placing mesh at the top 1/3 of the slab will help with "shrinkage" and placing it at the bottom 1/3 will herlp with tensile strength.

CW

congrats on your foundation. i would agree WAY over kill but to each his own. i wonder how deep your piers where and what size (i am guessing 12"/36" bell to a depth of 12 ft?). i would say the 30" beams are being wasted with the piers and the excavation that was done. the reason i say this is the load of the house is not really placed on the beams but transfered to your piers and their bell bottoms to the solid soil below. the excavation IMO is used improperly 90% of the time. if you excavate 2' then refil and compact to 95% in 6" lifts, that great BUT most of the time a pad is compacted only 12"-18" deep. now a 30" beam (depending on form hight) will penetrate deeper then the excavation. so why compact if your going deeper then the compacted fill? this will more then likely not be the case here. just depends on your form hight.

now the 4000 psi mix is not a bad idea BUT remember this is a compresive strength not tensile strength. 4000 psi will not hold up without proper reinforcement. i will guarantee your slab WILL crack at some point. it does not mater what you do concrete WILL crack.

you have a well built slab, it will last you as long as you will live there and then some. as long as you are happy with it and what you spent for it that is all that maters.

[cwrm4]

I did not use piers...I considered 12 x 24 beams + piers but went with 16 x 30 beams with no piers. Also, the form height was 1 ft above grade, so basically when we dug down for the beams we were digging out the select fill, which I put on top of the pads and then compacted again. Fortunately, I also hit pretty good soil about 20" down.

I do realize concrete will crack eventually...but hopefully not for a long time! I think put enough steel in there that I hope it will span any soil support issues that could (or rather, will) materialize.

[RedScare]

I did not use piers...I considered 12 x 24 beams + piers but went with 16 x 30 beams with no piers. Also, the form height was 1 ft above grade, so basically when we dug down for the beams we were digging out the select fill, which I put on top of the pads and then compacted again. Fortunately, I also hit pretty good soil about 20" down.

I do realize concrete will crack eventually...but hopefully not for a long time! I think put enough steel in there that I hope it will span any soil support issues that could (or rather, will) materialize.

What was your cost differential between the 16x30 beams that you went with versus piers under 12x24 beams?

[Specwriter]

i dont know where you got that WWM is placed to conduct heat from the core of anything. this statement is completly false. WWM is nothing more then reinforcement. there is no need to conduct heat AWAY if anything you want the heat of hydration to stay inside. the key is to keep the hydration going by keeping moisture involved. water curing, covering the slab area, curing compounds, are all made to keep the heat of hydration inside along with the water content.

i agree 1005 with your other statements just not this one. i have been an ACI, PTI, and ASCC memeber for years and have never heard of such a thing.

Rigas, I probably got that misinformation about WWM from a dumb structural engineer some time ago. Being a dumb architect, I am susceptible to being misinformed about such things. Thanks for setting that straight. Apparently, you and I agree though that too little attention is paid to how concrete work is done, especially in residential work, in this area. It's good to know there are some good concrete folks out there.

Contractors who maintain membership in professional and trade organizations such as ACI give a positive sign that they care about the quality of their work. Of course, it is still a good idea to check references and see examples of their work.

[rigas]

Rigas, I probably got that misinformation about WWM from a dumb structural engineer some time ago. Being a dumb architect, I am susceptible to being misinformed about such things. Thanks for setting that straight. Apparently, you and I agree though that too little attention is paid to how concrete work is done, especially in residential work, in this area. It's good to know there are some good concrete folks out there.

Contractors who maintain membership in professional and trade organizations such as ACI give a positive sign that they care about the quality of their work. Of course, it is still a good idea to check references and see examples of their work.

spec,

i have to appologize, i had a very bad day before i typed that and after re-reading i fell i was a bit harsh in my entire post. i am sorry if i offend anyone.

i am a firm believer in learning EVERYTHING you can about what you do (and other things as well). i am rather hard headed as wel though. i come from a long line of concrete contractors, my father owns a concrete contracting comapny which also is the 2nd-3rd largest reinforcement suplier in the houston area, and somewhere around #60 or so on the list of 2008's top 100 concrete industry companies (based on revenew). i worked for him for 10 years before opening my business 5 yrs ago. my grandfather was one of the 5 origional members/inventors of the post-tension institute and started in the concrete business in the early to mid 1950's. i started working for him, pulling nails for about $1 a day in the early 1980's as a kid in the summers.

in the houston area i have seen just about everything there is in residential concrete. i am working my way into learning more about commercial concrete.

one of my biggest pet peeves in concrete is overkill without reason. for instance, i placed a parking area under a home on pilings or stilts down in kemah. the "engineer" designed this parking area with a beam around the exterior, fine, he put 4#5 rebar in teh beam with stirrups at 12" centers (to many stirrups), then he had a 4" pad, fine, but he wanted a 16 ocew grid of #4 rebar 3/4" from bottom of pad, and 16" ocew #3 grid 3/4" from top of pad. this is fine but not in a 4" pad. he then requested 4000 psi concrete WITH NO FLYASH, no retarders, and no more then 4" slump. the heat index was 108 today! he then required the concrete to be water cured for minimum 48 hours and preferably 7 days. the area was 1904 sq ft. he also wanted saw cut control joints covering an area no larger then 200 sq ft. i talked them into at least going with a treated expansion joint instead.

all this for a parking area which (per the home owner) will be turned into a screened room with some lawn equipment in a storage in the back.

AHHHHHH they spent about $3000 more then they needed to.

[cwrm4]

What was your cost differential between the 16x30 beams that you went with versus piers under 12x24 beams?

The net would be have been close to an additional $2k or so...coincidentally the same price as the new table saw I am buying...I decided I would rather have the table saw. It is, after all, just a garage with a lot of storage upstairs (for now).

My neighbor put piers in his foundation, and hit water 8 ft down, so I kinda questioned how much support the piers would really add vs. beefier beams. (I'm pretty close to White Oak bayou).

[RedScare]

The net would be have been close to an additional $2k or so...coincidentally the same price as the new table saw I am buying...I decided I would rather have the table saw. It is, after all, just a garage with a lot of storage upstairs (for now).

My neighbor put piers in his foundation, and hit water 8 ft down, so I kinda questioned how much support the piers would really add vs. beefier beams. (I'm pretty close to White Oak bayou).

As you know, like you, I am building a 2 story garage. It will be 24x24, initially the 2nd floor will be empty, but at some point it will become an efficiency apartment or game room. Am I reading correctly that piers are a bit of overkill for a garage of this type? I am a firm believer that the foundation is the most important part of the building. However, if 16x30 beams will handle anything that Houston soil throws at it, I am not interested in wasting money on piers.

I ask for 2 reasons. One, I don't like to waste money if it provides no additional support. Two, my architect friend who is drawing the garage is pushing for piers. I would definitely put in piers on a house, as I do not believe slab on grade in Houston soils is a good idea (regardless how many slabs have been poured here). However, for a garage, where a slab is required, I am not so sure. Opinions appreciated.

[jm1fd]

By the way, the 28-day test came back at 5000 psi! I guess when the plant knows you are going to have it tested, they tend to err on the side of too strong.

So how exactly do they test the strength after it has been poured?

I know they can do a slump test on-site before it is poured. Are there any other on-site tests?

What does testing run, anyways?

[rigas]

So how exactly do they test the strength after it has been poured?

I know they can do a slump test on-site before it is poured. Are there any other on-site tests?

What does testing run, anyways?

a testing lab (same one testing slump) will take cylinders, leaving some on site in the current weather conditions and taking some to a lab where they are stored in "optimal" conditions. then at 7 days they will put it in a "press" and press it till it breaks and it records the compressive strength. they will sometimes do this again at 14 days and then again at 28 days.

red, IMO i would excavate a couple feet and compact a pad then you do not need 16x30 or even 12x30 but 12x24-26 will work just fine. if you are still concerned then beef up the pad and go 5-5 1/2" thick instead of the norm of 4". you have to remember concrete weighs ABOUT (not every mix is the same but average) 4000 lbs per yard. i have seen concrete crack under its own weight due to pour soil conditions. i do a lot of peirs in the heights area, sawyer heights, doing some right now in the 5th ward and we run into water at all different levels. it also depends on how much rain we have had. the water table in houston is very strange.