Home Page link

New concrete floor

Home| Search | About
Login Password
Register Now! Lost Password?

Building Construction - Building Construction Industry Discussions. 

Page 2 of 2       << first < 1 2 Bookmark this page:  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
New concrete floor fredy 11-17-2006
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by Bob Morrison on November 21, 2006, 12:31 pm
In a previous post Wayne Whitney wrote...
> By "go off like a rocket", I assume you mean set up really quickly. I
> thought that pouring conrete directly on a plastic vapor barrier
> typically delays the setting up of the concrete, as there is nothing
> to absorb the excess water used for placement. The sand layer on top
> of the vapor barrier would provide a more normal setting up time, as
> it can absorb some of the excess water. Have I got this backward?
>

No. You got it right. However, the tip about putting 2 layers of sand
with the vapor barrier between is a pretty good one.

BTW, ACI has issued new guidelines on using a plastic vapor barrier.
Basically, they are saying "DON'T USE ONE", unless you have a high ground
water problem and you have a flooring material that will have problems
with moisture (carpet, vinyl, wood).

In other words, try to take care of any moisture BEFORE it can migrate
through the slab. This will be the case in most installations, so in most
cases a vapor barrier is not needed.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com

Posted by Stuart on November 24, 2006, 10:14 am

> In a previous post Wayne Whitney wrote...
>> By "go off like a rocket", I assume you mean set up really quickly. I
>> thought that pouring conrete directly on a plastic vapor barrier
>> typically delays the setting up of the concrete, as there is nothing
>> to absorb the excess water used for placement. The sand layer on top
>> of the vapor barrier would provide a more normal setting up time, as
>> it can absorb some of the excess water. Have I got this backward?
>>
>
> No. You got it right. However, the tip about putting 2 layers of sand
> with the vapor barrier between is a pretty good one.
>
> BTW, ACI has issued new guidelines on using a plastic vapor barrier.
> Basically, they are saying "DON'T USE ONE", unless you have a high ground
> water problem and you have a flooring material that will have problems
> with moisture (carpet, vinyl, wood).
>
> In other words, try to take care of any moisture BEFORE it can migrate
> through the slab. This will be the case in most installations, so in most
> cases a vapor barrier is not needed.

I think Wayne may hose down the sand before pouring. Wayne and Bob, is that
a good idea?
Stuart//



Posted by Italian Mason on November 26, 2006, 1:46 pm
Sorry was out of town for a while..

No you are correct the sand layer on top does allow a more normal set
up time. The plastic accelerates the process greatly and on a hot day
concrete poured directly on plastic can damage the whole slab because
of the heat generation. To answer the question below (even though I was
not asked) yes you should spray down the sand or dirt or baserock or
whatever you are pouring over not wet wet but lightly moist.

Wayne Whitney wrote:
>
> > Sand should be put down under a vapor barior and on top of it under
> > to ensure the plastic is not torn on the jagged base and on top so
> > the concrete doesnt go off like a rocket while finishing it.
>
> By "go off like a rocket", I assume you mean set up really quickly. I
> thought that pouring conrete directly on a plastic vapor barrier
> typically delays the setting up of the concrete, as there is nothing
> to absorb the excess water used for placement. The sand layer on top
> of the vapor barrier would provide a more normal setting up time, as
> it can absorb some of the excess water. Have I got this backward?
>
> Thanks, Wayne


Page 2 of 2       << first < 1 2
Similar ThreadsPosted
Concrete slab for basement floor June 30, 2007, 10:25 pm
How to find if the floor is made of concrete from the external look August 8, 2006, 12:35 pm
Anchor Bolts - Commode To Concrete Floor September 19, 2006, 12:04 pm
Floating a 3/4" Solid Hardwood Floor Over Above Grade Concrete? December 19, 2006, 3:06 pm
Building stud partition onto tile floor with under floor heating July 12, 2006, 2:54 pm
Learn how floor tile patterns affect the look of your new floor. October 11, 2007, 3:39 pm
Nailing floor with glue versus screwing floor without glue--which is better? October 3, 2006, 9:36 am
Concrete driveway issue Any concrete experts? March 15, 2008, 9:48 am
Stamped concrete vs. concrete overlay? December 10, 2006, 11:47 pm
pouring concrete over concrete December 10, 2006, 5:34 pm

Contact Us | Privacy Policy

XML SitemapXML Sitemap