concrete floors

[rusty baker]

What do you think of houses built on concrete slab? We see very few of them here. They are considered below standard in this part of the country. My dad was a concrete man and he would have been the first to say that they were a bad idea. Go in to any over 20 years old and the floors are cracked. No concrete construction is ever guaranteed against cracks because it is going to happen. I realize they are cheaper to build. but I think they are a bad idea in the long run. Opinions?

[Lo Down]

I read an article on concrete where the author said that concrete does not crack if done properly........ and I think it is rarely done properly. I will try to find it. I agree that you can't guarantee against cracking. We have slabs around here, but most construction is not. I like wood myself.

[Tandy Reeves]

Rusty, I do not know where you live, but concrete subfloors if constructed properly is an outstanding floor. It is far more stable than joist floors. I would guess that over 60% of the home and commercial construction in the US today uses concret slabs for the floor. In my part of the country 99% of the floors are concrete.

As with any floor concrete if not properly constructed can be a bad situation.

[Jim McClain]

I have a friend who is a retired building contractor. All of his homes were slab construction and I hated them. In fact, I disowned him as a friend during the installation of flooring in his jobs. I hate slab construction, but a good slab is sometimes better than wood floor construction, depending on the material going down.

Slabs have 2 issues in their construction that I have always had problems with: control cracks and expansion joints. Yes, concrete slabs have cracks, but they are s'posed to be there and in specific areas. I don't know how or why though. There are also expansion joints that have a material between them that expands and contracts with the movement of the joint. I also don't know how or why about those either. I do know those must be "honored" in the installation of hard surface flooring that is attached to the slab in some way, or you will have problems.

I wish my friend was here to explain -- he's off traveling in his new motor home. Maybe we have another member that knows about these things. All I know is that concrete=+$$$ -- unless he's your best friend.

Jim

[Lo Down]

A lot of what it takes to keep concrete from cracking is consistancy of the initial earth substrate, compacting the sand, keeping the wire mesh suspended at the proper level, suspended evenly and even suspended with the proper material....... I recall the author not liking brick to suspend the mesh because it absorbs moisture out of the concrete. I will look for that article tonight after work. More to concrete than I though there was.

[Bud Cline]

In all fairness we need to consider that basements or deeply dug foundations are not practical in all areas of the country. For example southeast Oklahoma and north Texas are areas where basements would be cost prohibitive due to the location of natural occurring rock. I have seen areas of Texas where the soil-cover was not more than two to three inches thick, just enough to grow some grass. Tree planting was a major effort and very expensive.

Unfortunately builders in those areas are faced with the same escalating building costs everywhere else is and it is everyone's desire to maximize their profits and income at every opportunity. Therefore shortcuts are taken by most everyone in the business.

House slabs can be designed so that cold joints occur parrelling interior walls. Slabs could be reinforced with rebar rather than rewire. Clay soils could be impregnated with lime and compacted to increase stability and slow expansion and contraction under wet and dry conditions and seasonal changes. Slabs can contain fiber additives or post tensioning cables. Cement mixes can be beefed one sac at a time if so desired to improve strength of the slab. Slab thickness can be slightly increased to discourage cracking.

Problem is all of this costs more money.

When I lived in north Texas most every house there was on a slab, here in Nebraska people scoff at the thought of having a house built on a slab and slab homes offer nowhere to hide during severe weather season in this part of the country.

It goes back to the desire of a builder to offer quality in his work. Concrete slabs don't have to crack as often and as randomly as they do. They crack because efforts to stop or control the cracking are minimized by the almighty dollar and a desire to make money.

Just an opinion!

[Lo Down]

Couldn't find what I wanted. It was in my favorites, but guess it "expired." Looks like the page is not available anymore.
Found this..... has a little of the same info.
SiteLines: Laser Level Layout / Great Gadgets / Crack-free Slabs

[Jon Scanlan]

Alot of our floors in New Zealand are concrete and all our vinyls are full spread. Even the hair line cracks will show through. Some concrete is now poured onto slabs of polystrene. Sometimes chucks of loose polystrene are laying just under the surface of the concrete and crumble leaving holes when stood on. Great if you see them before the vinyl is laid. People reckon concrete floors are warmer, no wind blowing underneath. With domestic vinyls any cracks, joints etc will telegraph through the vinyl in an inverted "V". One of the main hassles is that the concrete takes 1 inch per month to dry one the building is water tight, no rain lying on the slab and with the speed they are buiding houses the concrete floors are still wet when we get there. We found that once the asbestous backed vinyls dissapeared which stretched and shrunk the imperfections really mirrored through with the plastic/fibreglass type backings as they would not stretch or shrink into themselves

[Jerry Thomas]

There is another issue with slabs that I wish the building codes would address. All hot/cold water lines should be sleeved so you can pull them out and slide in new ones if they get a pin hole leak. That pin hole problem has happened to me 3 times to date under my slab. I am dry as a bone on top but you hear water running like a hose is turned on. Insurance companies do not cover this problem unless you get water up inside the house.

Since October of 2001 (over 5 years) my wife has been living on 2100 sq. ft of bare concrete. We have no money left after all the repairs for a decent floor covering. I hope and pray this next year i can put something down for her. She has been a real trouper

There are over 30 other families in my subdivision who are having the same exact problem. I have met and talked with numerous officials and there is nothing that can be done about it.