Considering a crawlspace (perimeter foundation and wall, central piers as needed) in this land of slabs. Very rocky, stable soil in this region, so no expansive clay issues. Has anyone built a crawlspace in a predominantly slab area? Any difficulty finding concrete or rough plumbing contractors with crawlspace experience?

Have you wondered why it's a predominantely slab area? Personally I'm very much anti-crawlspace, I don't see any advantage compared to the many disadvantages of doing it this way. I would strongely discourage you from going this route as the potential problems may make for a long term headache.

On that note, if you are still adament about doing a crawlspace then I would suggest hiring either an architect or a knowledgable general contractor to co-ordinate this for you. Individual subcontractors will start pointing fingers at each other once something freezes up or you get mold down there. Having someone knowledgable about crawlspaces will do 2 things for you. It will most likely get it built correctly with the correct ventilation and it will give you a goto person if something goes wrong. If you don't have the goto person or company, the blame for any problem will eventually fall to you.

Edit: I forgot to mention that the only crawlspace that I will even look at building will have a concrete floor, conditioned and have an air exchanger run through it.

Thanks. Our architect is on board the project. Slabs are common in TX because of clay issues in many area and low cost. The building area drops off 4', so the crawlspace would have 4-5' headroom in most areas. I appreciate the vent/conditioning concerns. The disadvantages of a slab (buried plumbing, hard floors, insulation issues, issues on sloped site) are driving us to a crawlspace.

quote:

Originally posted by JayinMinnesota:
Have you wondered why it's a predominantely slab area? Personally I'm very much anti-crawlspace, I don't see any advantage compared to the many disadvantages of doing it this way. I would strongely discourage you from going this route as the potential problems may make for a long term headache.

On that note, if you are still adament about doing a crawlspace then I would suggest hiring either an architect or a knowledgable general contractor to co-ordinate this for you. Individual subcontractors will start pointing fingers at each other once something freezes up or you get mold down there. Having someone knowledgable about crawlspaces will do 2 things for you. It will most likely get it built correctly with the correct ventilation and it will give you a goto person if something goes wrong. If you don't have the goto person or company, the blame for any problem will eventually fall to you.

Edit: I forgot to mention that the only crawlspace that I will even look at building will have a concrete floor, conditioned and have an air exchanger run through it.

quote:

Originally posted by BillC:
The disadvantages of a slab (buried plumbing, hard floors, insulation issues, issues on sloped site) are driving us to a crawlspace.

Why do you consider these disadvantages? If you plan correctly, the only pipe to bury is the drainlines, which are buried once they get outside your house anyway. Hard floors - I'm not sure why this would be a disadvantage or an advantage. Insulation - there are far more insulation issues with crawl spaces than there are with slabs, I've never seen an insulation issue with a slab on grade. The sloped site just means you would use more fill before you pour the floor. But I'm sure the cost of a floor system is far more than the extra fill.

With all respect to Jay in MN with a very different climate than Texas, I can give you some insight at least for the Dallas/Collin County area as to slab vs. pier and beam (crawlspace). Your soils are considerably different than our area, which you mention,
but due to our climate, SA still gets some
notable soil shift, like we do.

Most TX homes--your area, ours, everywhere are slab, post-tensioned or otherwise, as they are the least expensive foundation. Pier and beam for TX is a step up. It is always advantageous
in a Texas build to have a pier and beam for
access to mechanicals (and elimination of breakage in the slab for same--happens all the time here, we probably contract 2 dozen or so expensive repairs per year for pipes broken within the slab. If you are planning on hard surface flooring--definitely for hardwood floors, and to a lesser extent for tile and grout, it is an advantage to have them laid over subfloor here (pier and beam), vs. laid over concrete slab, due to the soil shift, hence house movement.

As to insulation, there are many in the market today--closed cell foam, Icynen®, etc. that are
excellent with our nearly year-round A/C costs.
A to ventilation, Jay is right--in every P & B we do, there is a ventilation fan system--either with a manually controlled switch by the homeowner, or with a water sensor to trip the fan installed. With our very short, usually, winter season, you will also want the faceplates that attached to the cast vents for P & B.

The only downside we have run into(only on remodel, not new construction) and something for your architect to plan for, is any air condensor or other mechanical lines placement, so they do not have to run through the cast vent--too many critters in Texas to allow these holes!
Hope this helps your decision some.....