What are your thoughts?

[gto65goat]

My contractor just dug the garage footers.
Garage is to be 25' X 28'. (2 Car Storage and a little wood work area, not daily drivers).
He's specing 2500 PSI for the footer, and 3500 PSI for the garage floor.
He is also digging 3 equally spaced, garage floor support holes, approximately
4' X 4' X 3' deep, also filled with the 3500 PSI. (from front to back / middle).
Rebar to be placed into the drilled holes in the sidewall blocks, and rolled wire mesh too. I would like to go with a .100 thick, heavy duty vapor barrier, but can not find it in the Anne Arundel County area of Maryland. (Perhaps, one of the forum members would know?) .060 thick used in this area as the norm.
Anything I'm missing or should be concerned about?
Thank you,
John

 

[PAToyota]

Personally, I went with a steel beam with columns at the sidewalls so that I wouldn't have columns down the middle of my shop. Too easy to hit with car doors, have to work around, etc...

Sixty mil vapor barrier is fine.

 

[elsensei]

yeah get rid of those center supports. you'll hate them.

 

[MXtras]

Double it up and you are just a bit heavier than you wanted to be.......

?

 

[kbs2244]

I agree that you do not want any posts in the finished garage, but I didn't read it that way. It sounds to me that the contractor is digging holes for support pillars that will be UNDER the floor, on the center line if the floor. My questin would be why. It almost sounds like he doesn't trust his compacting to be done right and he wants support the slab in case the fill settles under the slab. I wwould get a reason for doing it that way. Any fill put under the slab should compacted to the point that it will never settle.

 

[gto65goat]

I agree that you do not want any posts in the finished garage, but I didn't read it that way. It sounds to me that the contractor is digging holes for support pillars that will be UNDER the floor, on the center line if the floor. My questin would be why. It almost sounds like he doesn't trust his compacting to be done right and he wants support the slab in case the fill settles under the slab. I wwould get a reason for doing it that way. Any fill put under the slab should compacted to the point that it will never settle.

kbs2244
You read my post correctly.
The 3 holes are for floor support only. No poles in the garage.
Contractor said he plans to compact every 6 inches of fill dirt added, but on all "his" jobs of this size (5") thickness...he adds the support holes.
Thank you,
John

 

[Bib Overalls]

Concrete filled support holes drilled undisturbed soil are specified on some plans here as well. Usually tied into an inegral "beam" with rebar running under a load bearing wall.

Usual and customary regional building practices generally evolve from experience. Assuming you are otherwised satisfied with your contractor let him do the job his way.

 

[Junkman]

Ask the contractor about using the wire mesh that comes in sheets rather than on a roll. The roll stuff has a tendency to want to curl and just isn't that good in my opinion. I have heard that it will get pushed down to the bottom of the concrete and then it also might just get too close to the top of the concrete other times. All this is a result of it wanting to stay rolled up.

 

[brownbagg]

who paying the bill, who ever that guy is, makes the rule. I would want 3500 in the footers too, its not that much more money, beside the bldg setting on the footers

 

[Junkman]

I agree with the 3500 PSI concrete for the footers. Also have them put a key way into the footers so when the walls are poured, it will keep them from shifting at a later date. This is done by putting a two by four into the wet concrete when the footer is poured. After it dries, the two by four is pulled out of the concrete. The depression that is left is known as the key-way. I would also consider having fiber mesh added to the concrete. It doesn't' cost that much and it does give it extra strength. I would also suggest that you are there when they pour, and that the contractor doesn't water down the concrete. When it comes from the mixing plant, it is calculated to have enough water to maintain the 3500 PSI rating. If the contractor has the mix watered down so it is easier to move around while pouring, that will decrease the strength of the mix. Also ask the contractor if he is going to use a concrete ******** on the walls. The ******** when properly used will help the concrete to level and will drive out any air pockets or voids in the concrete. Many contractors don't like to use them, because if it is over used, it can cause the stone in the mix to go to the bottom. Like any tool, it needs to be used properly and by a person that knows how to operate the tool. The more you learn about the project before it is done, and convey that information to the contractor, so he realizes that you understand the process, the less likely he is to cut corners. Make sure that both of you are in agreement on what will be done and how before the job. The last thing that you want to be doing is fighting with the contractor when the concrete is being delivered. Remember, that if everyone is happy the day that they pour the concrete, then you will get a better job. Don't forget to have coffee and donuts when they arrive, and also for the truck driver. Then have lots of cold bottles of water for when they are working. If the job is going to go past lunch time, don't be cheap. Have a few pizza's delivered and have some cold soda available. I can tell you first hand that spending $50 to feed the crew will be the best money you will ever spend on the project. These are the guys that are building your garage, and tomorrow they will be gone, but you will live with the quality of the work for many years to come. Keep them happy, and they will do a better job for you.