View Full Version : Hardi board over Concrete?
eric34
Feb 28, 2008, 08:18 PM
I am just starting to install the Hardie board on my new house and I have about10 sqft on the bottom that is concrete. I know how to install it on concrete but is it a good idea??
ballengerb1
Feb 28, 2008, 09:44 PM
You usually hang your first and lowest board so the nailing area still catches the lumber and hangs down over the seam between the concrete and rim joist.
the1unv
Feb 28, 2008, 11:39 PM
Don't install it on the concrete. Do as ballengerb1 says. Less time, Less effort and better looking product.
Mike
eric34
Feb 29, 2008, 12:23 AM
Well it's on the bottom corner of side of the house. I installed treated 2x4's in the foundation to help me with this but want to now if bad things will happen(mosture behind the siding. There will be a set of stairs going up the slope so it will look good.
ballengerb1
Feb 29, 2008, 08:42 AM
Maybe I am picturing this wrong but doesn't the pt 2x4 cause the siding to bow out at the bottom compared to the surface of the rest of the boards? When you mix Hardieboard and concrete there isn't much moisture can do to screw things up but try to answer my question the best that you can.
eric34
Mar 1, 2008, 12:03 AM
Sorry for not telling the whole story.. I put treated 2x4's in the concrete, screwed them to the inside of the forms so when you take the forms of there is wood flush with the concrete. This is normal, acoording to my carpenter.. I was just wondering if a person could get in trouble by going over concrete. It was poured last may but still has moisture to come out I'm sure.
ballengerb1
Mar 1, 2008, 02:33 PM
You should be OK with what you have done. Neither concrete of Hardie plank will be compromised by a little moisture.
the1unv
Mar 1, 2008, 05:46 PM
I agree with ballengerb1, should not have an issue. I would however, for my own take one simple step. Hardi plank, primed or pre-finished doesn't come with any finish on the back. I would throw a coal of exterior primer or paint on the back of the planks coming in direct contact with the cement walls. This will allow you to sleep better at night.
Mike
eric34
Mar 2, 2008, 06:45 PM
I was going to throw some tar paper in between them... Thanks