Hardie Panel to paint or not to paint ?

[Punamom]

I have some unprimed and primed Hardie siding and was wondering if its better for (mold) maintenance to leave it as is or primer and paint it?

Also wondering if tar paper is a better (or equal) vapor barrier than the house wrap.

Thanks in advance []

[pslamont]

I will offer up a NO on the tar paper for house wrap. The whole point po Tyvek (or like) wrap is that it is a one way moisture barrier; that is it breathes OUT. Moisture does not move in but extra moisture moves out. At least that is my understanding....

Just another day in P A R A D I S E !!

[Carey]

Pam, yuppp... in the late seventyies & early eighties some builders were wrapping houses in plastic sheeting. Those houses didn't breathe & soon had all sorts of problems, including mold growth....
hence the overwelming use of tyvek (tar paper is much like plastic for vapor transmission plus the paper can have mold growth, unless there is an inhibitor...)

Also, the Hardie panel product is to be painted or stained (unprimed is the Hardie backer, it is to be used for tile adhesion or primed & painted) per the literature from James Hardie...
We are using the Hardie panels inside & outside, for the durability & non-mold growth (& inside because of unusual walls, they fit in the walls...), flat primed panels inside painted, outside primed cedarmilled stained with an approved stain for the primed panels....
A good paint or stain with a mold inhibitor is best here... be aware that although the Hardie backer does not support mold growth, the unprimed surface is more porous & can entrap moisture & dusty things that CAN support mold growth... the porousness is better for adhesive adhesion, thus better for tiling.

[JWFITZ]

You need to paint it. It absorbs water. It's basically cardboard in concrete.

Actually, I've seen used tar paper used extensively in many climates as a vapor barrier. It's harder to work with than tyvek. Tyvek is very often seen put on backwards and inside out, and seems to make little difference.

Nothing will stop mold in this climate, as far as I'm concerned. Build so it won't bother you.

[Rob Tucker]

When you paint cement product like Hardie panel you need you use a alkaline formulated paint or primer. Wood is acidic. Cement is alkaline.

[Punamom]

Thanks everybody learn something new everyday, I guess old school is not always better.
I'm jus looking for as low maintenance as possible something I never considered till I got older, but looks like I'll be 80 and climbing up on the ladder to paint the damm house again lol.

We did our house in t-1 11 without a moisture barrier.
But I got the hardie siding (8" x 12'??) at HPM for 2$ a board because it was a special order/closeout, but it is unprimed.

It was so cheap I had to get it, one I hate the t1 11 look, I also don't like the thick 6" siding look, I want the 4" or less lapboard siding look or maybe a combo board and batten (2 story).
Can I do 4" lap or b&b with the siding ?

Do I even need a moisture barrier between the old t1 11 and the new hardie siding? ( i think I would like one)

Now I'm wondering if there is a cheap substitute for underlayment for laminate floors (going on painted cement) can I just use plastic sheeting or is some kind of cushioning needed.

I really hate that packaging material that everybody throws away repackaged as expensive flooring underlayment! Not to mention the products out there that you don't really need to use. There just invented cause somebody will buy them. But then again I sure don't want more problems down the road. Just good knowledge and on the cheap.
Thanks so much for your help!

Thanks Kat!

[EightFingers]

From the Hardie site:

PRIMING & PAINTING
DO NOT use stain on James Hardie® products. James
Hardie® products must be painted within 180 days for primed
product and 90 days for unprimed. In addition non ColorPlus®
product versions of HardieshingleTM Siding require a field
applied prime coat. 100% acrylic primers and topcoats are
recommended. Do not paint when wet. For application rates
refer to paint manufacturers specifications. Back rolling is
recommended when paint is spray applied.

Hope this helps, you can visit the Hardie site at http://www.jameshardie.com

[DanielP]

I have been using TYVEK for many years. I would not suggest using it between layers of siding or over solid shear. There seems to be some problems with capillary movement of vapor that becomes liquified between the TYVEK and the shear, or in your case, the T-111. I have been told that TYVEK no longer meets code in California. Code now calls for 15# felt. 15# felt would be my suggestion.

Dan

[JWFITZ]

I'd agree with that Daniel. Bugs don't like tar paper much either. One of the big problems with any light sheet like tyvek is that just because of the light thermal mass it's prone to sweat, and that's not a good thing here for sure.

[Punamom]

THANK YOU!!!!!