Replies

1. GBA Editor
   MALCOLM TAYLOR | Mar 26, 2025 11:03pm | #1

   Cottagebuilder,

   I haven't used it, but from the promotional material is looks to be by far the densest batt I've seen - more akin to board insulation than batts. I'm not surprised you are having some difficulties installing it.

2. 
   Chris_in_NC | Mar 26, 2025 11:28pm | #2

   I remember with the R30 Roxul batts (they seemed denser than the other brands) that it helped to start one side of the batt part way into the stud bay (with the batt at a small angle), and then press the leading edge of the other side of the batt to start it into the bay.
   It's easier to compress an edge by hand than to try and compress the entire flat sides of the batt at once, as you're able to put the same amount of force into a smaller area (an edge, a corner, etc.). Also allows you to push with both hands on the same edge instead of squeezing with one hand per side.

   I'd imagine the TimberBatts may be similar enough for the same method to work. I'd love to try out the TimberHP stuff sometime.

3. Expert Member
   BILL WICHERS | Mar 27, 2025 09:30am | #3

   I haven't used this stuff either, but it looks almost like "wood foam" to me, more like a rigid material than a fluffy batt.

   What I've done with the very dense/stiff Owens Corning mineral wool batts (my favorite kind, BTW), was to push the two sides together a bit prior to install to sort of bow the middle of the batt out. Press that in, let it pop back into shape between the studs. That usually worked well to get the back corners filled. Trying to stuff it all in flat tends to deform the back corners and leave voids.

   The installation videos will have perfectly aligned and spaced studs, and they'll be spaced to fit the batts perfectly. This is great for "illustrative purposes", but in reality, studs aren't all perfectly straight, and the spacing isn't perfect, either. You're going to have some batts that are looser or tighter fits than others. I have sometimes used a piece of luan (~3/16" plywood) as a sort of shoehorn-like insulation installation tool that I use like a ramp to help slide the batt into place. You could try that too. The idea is to make a "ramp" with the luan so that the batt doesn't catch on the outer face/edge of the stud on one side, so that you can push it into the cavity more easily.

   Note that it's common to have to trim batts to fit in some places. There is a bread knife I often recommend for this in these forums. I'm not sure how well it would work on the wood fiber batts though. The batts should be a snug spring-like fit, but not so tight that you have to mash and deform them to get them installed. Ideally the batt should be it's original pre-installation shape after installation, without any big creases or voids.

   Bill

4. 
   Cottagebuilder | Mar 29, 2025 10:16am | #4

   Hey all,

   Thanks for the replies. Bill, I like your idea of using the luan, I give that a try. I thought insulating was going to be easy! Boy was I wrong.

   Let this be a fair warning to anyone who wants to use TimberHP. It’s nice stuff but you’ll need to have patience and time to install it.

1. Expert Member
   BILL WICHERS | Mar 30, 2025 01:05pm | #5

   Insulating WELL requires attention to detail. Just take your time and you can do a good job -- it's not complicate, it's just fussy.

   I would treat TimberHP the same as mineral wool or any other material: it has a few unique properties, but that doesn't make it a bad product -- you just need to learn to work with it. I would have no problem using it myself on any of my own projects, I just haven't had a chance to see it in person yet. I like the concept of the stuff.

   Bill

1. GBA Editor
   MALCOLM TAYLOR | Mar 30, 2025 01:21pm | #6

   Bill,

   It does sound like it would be exponentially harder to use around things like pipes, wiring or blocking where less rigid batts would more easily conform to their shapes.

1. Expert Member
   BILL WICHERS | Mar 30, 2025 01:25pm | #7

   True, I like to think of it as "wood foam", so you'd have to carve it, not do the usual "split the batt and stuff it in" method. I see too possible solutions:
   1- Get a few mineral wool batts, then use those in the tricky spots instead of the TimberHP material.
   2- Carve gaps into the TimberHP material to clear around tricky spots like pipes or blocking, then fill those with canned foam when done to avoid having voids in the insulation.

   Either method should work, and would avoid the added complexity of working with the TimberHP material in tricky spots.

   Regarding wiring specifically, it may make sense to talk to the electrical contractors if you're planning to use TimberHP insulation. Request that electricals be run on top and bottom plates and the sides of studs instead of through the air spaces between studs. This does complicate the electrical install a bit, but would avoid the need to split the batts in as many places.

   Bill

1. GBA Editor
   MALCOLM TAYLOR | Mar 30, 2025 01:39pm | #8

   Bill,

   That's really the best way to go on any installation if you can convince the electricians to do it.