Post wraps with Hardi cement board? Good idea?

[JoshAndrews]

have you guys ever done that and had success with it looking good and going together well? How would you nail/bond the corners together other than just shooting them?

Have you ever run into a customer that has a love affair with cement board products? A lot of people think it's the silver bullet for everything exterior these days. Personally I love cypress trim boards, but I'm weird.

This customer wants us to redo the trim on their open carport, which includes 9 ft. tall posts with base and crown wraps, and wrapping the headers (24'x24')

We'll be pulling off the Mirtec that has only been there for about 10 years because it mildews so easily and has chipped really badly.

We'll be swapping the solid 6x6 PT posts for laminated 6x6s which will remain stable and straight down the road.

Help the brother out if you have any pointers! Thanks a lot

[charles]

By cement board, do you mean the lap siding or trim? I've done it either way, but of course you can't nail the corners of the thinner material. Hardie says you can nail the corners of their trim boards, but I haven't done that and find that caulked corners look just fine. They make trim boards in more than one thickness - I think I used 1". Can post a photo if it would make you feel better.

P.S. Are you laminating the posts yourselves, or buying something pre-made?

[Catspaw]

Show your customer this picture and maybe they won't love fiber cement quite so much.

The original builder of this house decided to use fiber cement on all the places where he knew wood would rot because it was too close to the ground. In less than five years the fiber cement turned to mush. And if you think Miratec chips easily...

I would try to talk them (and yourself) into a PVC post wrap. I've used these but there are other brands:

http://www.kleerlumber.com/trimboard...kleersnap.html

- Rich

[dgbldr]

What Rich said.

[charles]

Show your customer this picture and maybe they won't love fiber cement quite so much.

The original builder of this house decided to use fiber cement on all the places where he knew wood would rot because it was too close to the ground. In less than five years the fiber cement turned to mush.

Agreed that FC should not be used near grade, but Josh can make the baseboards PVC and still use FC for the wraps, holding them the required distance from grade.

[JoshAndrews]

By cement board, do you mean the lap siding or trim? I've done it either way, but of course you can't nail the corners of the thinner material. Hardie says you can nail the corners of their trim boards, but I haven't done that and find that caulked corners look just fine. They make trim boards in more than one thickness - I think I used 1". Can post a photo if it would make you feel better.

P.S. Are you laminating the posts yourselves, or buying something pre-made?

We'll be using premade laminated posts. Pretty pricey, but our suppliers around here usually keep them inside and they're pretty dang dry. Building them on site is too close to splitting hairs for me while we're busy.

I'm looking at 3/4" Hardi boards unless one of you guys advises me otherwise.

I really like that idea of PVC at the bottom.

While we're on it, do you any of you guys like any species of wood more than PVC or Hardi in different scenarios?

How would you guys construct those corners and nail/glue them together where you join the Hardi material? Maybe a heavy duty adhesive with trim nails?

[charles]

Where are you buying your premade laminated posts? And why do you feel the need to nail/glue the corners together? Like I said, they do just fine with caulk.

[JoshAndrews]

I was talking about wrapping the treated column with Hardi vertically, but as I'm typing this I'm thinking I should just buy an 8x8 and paint that.

[JoshAndrews]

I had a brain lapse and didn't think about a treated 8x8 opposed to wrapping a 6x6 to get the size I'm looking for.

[charles]

No, you are wise to laminate and then wrap. Very hard to get treated timbers of any dimension that won't warp and twist.

[Bill Robinson]

Not sure what is available in your market however if you can get FOHC treated they are pretty stable.

[J.Buesking]

I've done a bunch. While they have all those requirements for height off grade for the most part I've been able to push the limits.

On a concrete porch I've had good results just keeping them 1/4" off the porch. As long as the hardie can dry and doesn't stay wet you are fine as been my finding.

Ofcourse each situation is different.