Doing a raised floor vs. and slab on grade I believe gives one a more comfortable floor to stand or walk on. If there is moisture close to ground level, the raised floor will not transmit the moisture directly into your living space. Also raised floors make it easier to route heating and cooling ducts, wiring, and plumbing. This approach makes for easier remodeling of those systems as well. The raised floor tends to be a more expensive approach construction wise vs. the slab on grade though.

as someone that owns a beach house built on a slab 30 years ago, it is very difficult to remodel being on a slab. we couldn't even run a water line to the refrigerator for ice maker. I vote foundation.

Having a crawl space gives you so many more options if something should go wrong or you want to make changes down the road. The floors are also much warmer, although you may not have to worry about that so much.

There are pros and cons for each system. If you live in an area that has a flood threat, a raised floor makes sense. If you live in an area prone to termite infestations, I prefer a slab on grade at a proper slab elevation above the finish grade. I also prefer a monolithic slab with a proper turned down foundation.

Slabs are less expensive than a good raised floor. A crawl space does allow access to utility lines, and space for AC ducts (which I detest coming through the floors). It also becomes a breeding place (dark, damp) for all sorts of living things (roaches, spiders, snakes will find an entry, sometimes raccoons or possums and the most fearful.....mold).

A properly installed slab is no more a moisture conduit than a properly installed crawl space. It all depends on the installation.

If you do plan on a crawl space, don't scrimp on the height. Provide a minimum of 24-30" BELOW the underside of the joist or floor trusses at the lowest point. Trust me if you have to get down there and work you'll appreciate the extra space.

I've installed both and I won't install your typical crawl space. If I have a slope to the site, I'll include a french drain along the low side piped out to a natural grade point to drain. After cleaning the space of all rocks, debris, wood cuts, etc.,etc. I'll provide a moisture barrier over the entire crawl space with a 4" layer of sand on top of it and I'll provide lighting fixtures ( at least 2) under there. I've never had any complaints from the home owners.

I'm renovating our house now and it's on a crawl space....30" clear space on the good end, 12" clearance on the not so good end. Everything is run under the house. Copper line on the ground, ducts crammed in there.......it's all most impossible to work there......and lots of crawly things. I've been under 4 times, once to replace a drain line to the kitchen, once to put in new supports for columns and beams to replace 2 load bearing walls that were taken out, and twice for electrical.
Every time I've come out cussing the builder who built this home in the 1950.

My next house will be built on a raised plinth with a slab on grade.

Just bought a cabin with a raised wood foundation. My question is we just ripped up the interior carpet and would like to sand and varnish inside foundation for interior floors instead of carpet or tile. Is it possible? Can i use my foundation and not have problems with moisture or draft? My inspector said we have good insulation underneath but did not go into details. If I can do this can I fill the gaps inside with something to help keep dirt, moisture, and air inside? I need something to be expandable, no shrinkage, sandable, and stainable The gaps are not huge just normally.

Strangely, I agree with all of the above comments made but feel compelled to add one small detail. Have the soil tested before going much further and have a competent structural engineer interpret the results. If budget is an issue, cut a corner somewhere else, but don't cheat on your foundation!

I love our raised foundation. Our home is almost 100 years old and has zero foundation work needed. We are doing a remodel and it is so easy for them to route the electrical and water pipes. Also we live in a high moisture area and we never have problems with mold. Our contractor says the raised floors allow for the air to circulate.

Im just sitting here shaking my head in disgust at the stupidity of most of the people here opinion or not. As a retired contractor, I am going to spell the truth out to you once and for all because i detest the new generation of contractors whose only goal is to deceive for money. Now the truth, Ok, which is better slab or crawlspace? This should be a first grade answer, but of course the contractors will say crawlspace. Think about it for a second. You would rather have a dark-damp-creepy - dungeon underneath your floor that promotes every living scary creature known to man. Spiders - snakes --VERMIN!. Yes, for sure we all love em. Heres the thing, Anyone who wants a crawlspace needs to have their head examined. Once this dungeon floor starts to sink you will have hell to pay. Try leveling these floors and you get all kinds of problems from cracked drywall to structure and foundation problems. With a concrete floor, you wipe away most of these problems for good. Even major cracks can be fixed within 30 minutes these days. So do you want to know the real reason these vermin contractors dont want to tell you the truth of why they really prefer crawlspaces? Its all about the MONEY. Do your homework. Pouring a slab is not even a 1/4 of the cost of a prehistoric crawlspace and thats the bonifide truth. The contractors of course want you to pay more ---repeat ---pay more! As for repairs to pipes with a slab --you can reroute them using a third wall which is how many are done modernly in many states today. Of course they wont tell you that either.

Thanks Bing for your fascinating perspective, but in soil conditions where the potential vertical rise (PVR of the soil when wet) is anywhere between 5" and 14" (like Las Colinas here in the Dallas area) it would be suicidal to use a slab. I might suggest that people concerned about this issue consult a soils engineer and follow closely their recommendation. P. S. - the question was asked in 2012, so perhaps Ms. Burks who was asking the question, already has made a decision.

5 years ago..... how did i find this?!?!?