Warmboard plywd. diaphragms

[Gillespie]

Hey I recently began consulting on a project where the architect is demanding we use 1.125" thick Warmboard.
Which is 1 1/8" plywd. with the PEX tubes recessed in.
It is APA rated for 3/4" plywd. values.

I know this product is real expensive and has many installation requirements. I'm more a fan of the infloor track systems by warmboard.

Other than the energy aspects of these systems does anyone have any experience with Warmboard plywood as the structural diaphgragm.

Gillespie

 

[msquared48]

I looked at the website and ER report. Professionally, I have never used the product. It looks to be a product designed to replace heated floor systems using copper or plastic pipes embedded in concrete.

In spite of the ER ratings, I am suspicious of the ratings and material for several reasons.

1. Beneath the routed groves, there are only two or three plies to take the shear across the panel to the next 12" section. The table values in the report seem too high to me with this situation.

2. I would be very concerned with mold and compromising the integrity of the floor diaphragm should any leaks occur with time, and they will occur.

3. In the section shown in the site, the 12" wide sections of the 4X8 panels span across the TJI floor joists. The wood flooring then spans across these 12" wide sections. Normally, wood flooring is placed across the joists too, not parallel to them. This will give a weaker total floor system, but apparently is necessary here to avoid nailing through the piping with the hardwood flooring nails.

4. How is any expansion/shrinkage handled at the marriage points of the 4X8 panels where the tubing is connected?

I wonder what insurance companies say regarding the product.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Gillespie]

Any experience with the warmboard from contractors/installers?

Especially if someone has experience with Warmboard and the alternate infloor track system (Wisbro etc...)

D