Multiple layers of insulation board

[kebwi]

So, I ordered eight pieces of 2" board (InsBlock 19) and received sixteen pieces of 1" instead (w/o advanced notice so I don't know if it was an inventory mistake or if they intentionally sent me replacement for out-of-stock 2" without notifying me). Northwest Ironworks provides several packages and this is clearly one of their packages (16x1", 10x1.5", 8x2", 5x3").

Anyway, so now I'm thinking about layering multiple 1" boards to make my hearth insulation and I'm trying to anticipate any problems that might result. Does anyone think I will have trouble with the boards sliding around against one another in a way that will make it difficult for me to hold things together cleanly during the construction process?

Or is this just not a problem at all? Mostly I'm miffed they didn't send me what I asked for.

Thanks.

[CLARIFICATION: I contacted NW Ironworks. They said the shipment was not an error, that their 2" is actually 1" glued together and their 3" is 1.5" glued together. I'll have to check when I get home to see if it is actually "glued together", I don't recall at the moment.]

[Les]

Re: Multiple layers of insulation board

It won't be a problem. With the amount of weight sitting on it, it's going nowhere.

Les...

[altamont]

Re: Multiple layers of insulation board

Multiple layers offers an opportunity for improvement.

Lay each layer on top of each other but rotated at 90 degrees. This gives a huge reduction in 'straight-through' joints resulting in slightly better insulation.

Sorry for not posting this reply sooner.