Comfortboard 80 actual thickness
callumshill
| Posted in General Questions on
I’m planning on install 2 layer of Confortboard 80 1.5″ on the exterior of my house and assumed that it was that thickness. However I just took my tape measure to a bundle and it looks like the sheets are closer to 1.25″. Did I just get a bad batch or is that how thick they are?
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callumshill,
From their spec sheet it looks like it comes in both: https://www.rockwool.com/syssiteassets/o2-rockwool/documentation/technical-data-sheets/residential/comfortboard-80-non-structural-sheathing-continuous-insulation-techdata.pdf
I purchased 1.5 inch from my local supplier and they sent me 1.25 inch by mistake. (I could not find markings on the packaging indicating the thickness.) I eventually did receive 1.5 inch and it measured the correct thickness dimension. If your material is measuring 1.25 I would guess you were supplied the wrong thickness.
I just double checked and it's labeled as 1.5". I got it at Home Depot and they also list it as that size. It's kind of strange. I'm going to reach out to Roxul and Home Depot and see what they say.
callumshill,
Thank God you thought to check.
Exactly, I was doing a mock up for my window flashing and realized that it was not 3" thick!
Always, ALWAYS double check. The old saying "trust, but verify" is important here. I know of a datacom cabling company here back in the 90s that was contracted to wire an entire school district's new computer network, many thousands of individual network connections in dozens of buildings. They failed final inspection. What happened? They had installed riser rated (CMR) wire everywhere instead of the required plenum rated (CMP). All the boxes were marked, and it's printed every three feet or so on the wire too. The inspector (and since these were schools, it was a state level inspection) caught the problem and failed them. The cabling company declared bankruptcy, went out of buisness, and the bonding company paid for a new company to come in and replace all the incorrect wire with the right stuff and basically redo the entire project.
Someone from the original cabling company didn't bother to check what material they picked up from their wire distributor and it caused such massive losses the company went out of biz as a result.
The moral: ALWAYS ALWAYS double check the material that is supplied/delivered to your jobsite! Mistakes happen, and it's always best to catch things early before they become BIG problems to fix.
Bill
I've used both 1.5 & 1.25 inch rockwool board. Both thicknesses exist. If you bought 1.5 they should take it back and send you right thickness.
Not that you've asked this, but just a word to the wise, and forgive me if you're well aware of this: Rockwool cb80 is a bit squishy, and you'll want to compress it a little with your strapping to firm it up. I've had it absorb a lot of the energy from my siding gun which prevents the nails from being set correctly. With 4" rockwool (e.g.), I compress it about 1/4", which seems to help.
Good luck!!
Here is an update. I've talked with the Rockwool Rep for my area and he confirmed that it is indeed supposed to be 1.5" thick so I've returned what I had and got some new bundles. They are the correct so far. Thanks to all for the feedback!