Flexboard for architectural panels

Stability and strength of flexboard and similar materials. November 24, 2002

Has anyone had experience with Flexboard (Kerfcore) for architectural wall panels? I would like to use it and wonder if it is stable. Are there any problems with the panels warping, etc?

Forum Responses
I cannot speak for Kerfcore, but we have done wall paneling jobs with kerfed FRPB and MDF cores with no problems. The key seems to be using enough Z Clips during installation, and doing a good job field measuring and templating the radius. Keeping the sheen down will help reduce the appearance of telegraphing.

The jobs we have done have had radii usually between 25-75', so we make a radius buck, lay the kerfed panel in the buck and apply white glue across the kerfs and add backer, followed by edging. They are fairly stable, but must be shipped and stored on the bucks or they will start to flatten.

As always, as long as you balance the panels, the largest variable will be the site environment, which is out of your control.

We did a job a year ago where we had the panels laid up on Timberflex, then the customer put them on hold so the panels were wrapped in plastic and not opened for about 4 months. When we finished them, we got blue lines in the maple that the veneer house attributed to the rubber gassing off - it was a weird problem and when they did a sample we didn't have any trouble. We were never sure what the actual cause was but we had to get two rooms of paneling redone.

Our application was raw veneer to the face of Timberflex and backer to the back with PVA glue line. Kerfing 1/2" MDF worked fine for us.

From contributor W:
We do radius wall panels and a lot of radius desk and reception areas with walls. They are up to 25 feet with 200 to 500 radius. The best thing that I have come up with is using layers of 1/4" MDF to make the radius. For a tighter radius there is a new product from Europe that is 1/4" MDF that has 1/16" kerfs on back with about 1/8" between and 1/16" of material still connected. This stuff will make a very tight radius, but you have to learn how to use it because it is really too flexible and does not work well on a large radius. The neat thing about it is if you have a form you can glue layers of it together and it will hold a form on its own.

We have used a combination of 1/8", 1/4" maple ply and Wacky Wood. Laminate schedule is based on laminate thickness and radius. Wacky Wood is unidirectional plywood.

We have used TimberFlex several times with great success. We supplied Disney Quest Chicago with two floors of curved wall paneling. It was VenTec veneer pressed on TimberFlex. The installers simply glued it to the walls with construction adhesive. Someone made a good point above about dulling the sheen down to eliminate any telegraphing.

Contributor W, we recently purchased some “Neatform” kerfed 1/4” MDF for a job and are a little reluctant to use it. This looks like a great new material and we were excited about it. The application is curved stringer panels on a large winding staircase (not a structural application). Our concern started when we found how weak the material is, as the kerfs break out very easily. Even if laminating multiple layers of this material, or laminating to bending ply, will these kerfs break out with the normal movement of the material as it expands and contracts over time? This was brought up by one of our top guys here working on the stair, and is a valid point that deserves some thought. Some of us think it is not much of an issue, but no one is willing to be responsible for it failing as this is not something we would ever want to have to replace. I still think this new material has great potential, but would like to see it proven in the field a little more. What do you think?

From contributor W:
We have used it on a large radius wall. I noticed after several layers that the material between our studs that were about 6 inches apart was weak. This material must have a backer sheet of some sort to hold it together. I noticed it glues and holds together better back to face than the way the guy from Europe explained it to us. I like using 1/4" MDF better. The 1/4" kerfed material is good for making forms or small tight radiuses. Used in the right place I think it will be a good material. It does require a lot of glue to get between the splines and this helps hold the face of the material on. The key is a lot of glue and no nails, just clamps. We did glue a form and drill a Blum hinge hole in it to test the structure. It drilled fine and did not seem to tear the material up.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
We use kerfcore a lot. It is the best product we have found for making curved door panels. The smooth surface paints out very well and takes veneer nicely.

We glue up one 1/4" sheet on the front, one 1/4" sheet on the back, and one 1/4" bendable poplar in the middle. We wrap this around the face of our curved cabinet with a few brads and straps. Most importantly, we use polyurethane glue (like Gorilla glue) because it expands and fills minor voids, therefore we do not need to clamp the form a lot for a sucessful glue-up.