DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   Slab, footer, block, insulation, vapor barrier & me! (http://www.diychatroom.com/f19/slab-footer-block-insulation-vapor-barrier-me-69477/)

TinaRap 04-20-2010 03:30 PM

Slab, footer, block, insulation, vapor barrier & me!
 
HELP would be so appreciated. I'm building a 12x20 art studio/office in central WV. I want it to be warm and dry, and, I only want to do it once, so I want to do it right. The location ground is solid and not damp. The Amish will build this - they have put up two cabins for us, but they built them on concrete blocks set on the ground, raised up about a foot from the ground. I don't think this is a good idea for my studio, as the floor won't be warm (you can't get under there to insulate) and I will have a heavy floor load with books and stained glass.

I am weighing price & benefits of a low footer/foundation wall or a footer w/a course or two of cinderblock or concrete piers set on foundation concrete tubes or a slab floor.

I am weighing the insulation issues as well. The Amish come and build in one day over your previously prepared foundation (whatever type you choose). You do not have the opportunity to have them stop while you somehow crawl under the joists to do any work.

I do not want a mold problem. I do not want a moisture problem.

I am thinking of a low poured footer/foundation, insulated on the outside with rigid insulation (1"?), dampproofing the footer, laying down a polyethylene vapor barrier on the ground and up the sides, and then letting the Amish construct the floor (2x4s w/OSB) on top of this. I can install vents through the foundation wall, if needed, but from what I've researched, it's best to leave it all sealed up. This will be 1' - 2' high and inaccessible once finished.

What do you guys say? Nothing has been done or purchased yet, but I'm anxious to move forward?

Many thanks in advance, Tina

Wildie 04-20-2010 08:37 PM

My preference would be a slab, poured over 3" XPS insulation!

When I built my attached garage and laundry room in 1978, I used this method and have been very satisfied!
No worry about varmits getting underneath! And the insulation has already been taken care of!
You could even consider putting in heating cable, while you are at it!

TinaRap 04-21-2010 07:49 AM

Thanks for your feedback. Yes, if I do a slab I'll do radiant heating - we have that in one of our other buildings and it's WONDERFUL!! But, the contractor said I'd need a 6" slab if I was putting radiant in. Do you believe so? Of course, that adds to the price! What thickness slab is needed for a small (12' x 20') building if radiant heating is going in?? And, what is XPS insulation?? Is it rigid styrofoam?

stuart45 04-21-2010 08:10 AM

I would agree with Wildie that a poured slab with insulation and a vapour barrier is the best way to go. This is the most common type of floor here.
If underfloor heating is required, a 4 inch slab is laid first, and then a 3 inch sand/cement screed is put over the top of the pipework.

TinaRap 04-21-2010 08:42 AM

Now you're confusing me. A 4" slab with the radiant tubing ON TOP of it? My understanding is the radiant tubing is IN the slab, along with the wire "fencing". Please explain a bit more and why you'd do it in two slab pours. Thanks for answering!

stuart45 04-21-2010 12:07 PM

1 Attachment(s)
Concrete floors here have traditionally been done with a 4 inch slab and then a sand cement screed here. You can better a better finish like that and also if there is a problem with the pipework it is much easier to break up the screed.
Attachment 19779

TinaRap 04-21-2010 12:17 PM

Thanks so much for that picture - it really helps. So this type is poured in two pours? How many days apart? I doubt if our forms guy here in rural West Virginia has ever poured 2 layers for something like this, but I'll find out. Now, what is this "sand cement screed mixture?"

Could this top layer be my finished floor? If not, what do you (or anyone else reading this) recommend for a floor finish? I'd be happy with wood planks (over firring strips?)

stuart45 04-21-2010 12:22 PM

The mix is 3 flooring sand 1 portland cement. The screed can be put on a week later. It is the finished floor, although normally carpeted or tiled.

TinaRap 04-21-2010 12:26 PM

Thanks again. IF our guy never did this, and insists on one pour, what thickness floor would be needed, without overbuilding?

stuart45 04-21-2010 12:30 PM

I would guess about 6 inches.

TinaRap 04-21-2010 01:27 PM

Many thanks again. I'd like to hear what anyone else may suggest to my original post regarding slab vs. low foundation wall vs. cement block piers.

Wildie 04-21-2010 04:11 PM

Quote:

Originally Posted by TinaRap (Post 431436)
Thanks for your feedback. Yes, if I do a slab I'll do radiant heating - we have that in one of our other buildings and it's WONDERFUL!! But, the contractor said I'd need a 6" slab if I was putting radiant in. Do you believe so? Of course, that adds to the price! What thickness slab is needed for a small (12' x 20') building if radiant heating is going in?? And, what is XPS insulation?? Is it rigid styrofoam?

Yes, that is correct!

Ithink that if you are installing hot water lines in the floor, it is done with two pours, but I believe electric heating cable can be done with one pour!
I have no experience with this, so perhaps others will advise you!


All times are GMT -5. The time now is 01:31 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved