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ENGINEERED FLOOR BALANCING2/2
I'm a cabinetmaker being asked for my opinion on engineered flooring. Species will be white oak up to 12" wide. Ultra high-end job.
I've attached a photo of 3 products from 2 different vendors.
Type 1: 7mm solid oak faces with 7mm solid, cross grain core
Type 2: 4mm solid faces + 10 mm solid, cross grain core
Type 3: 4mm solid faces + 12mm Russian Birch core
My question is - The construction of Type 2&3 balance the approx. mass of solid wood with the approx mass of the core. The vendor says the ratio is about 45% solid oak (by mass) to about 55% cross band core or ply core. They argue that this provides a better balance than the construction of Type 1.
This makes sense to me but I'd like opinions. I see the appeal of the thicker wear layer which would allow more sanding and refinishing but that's not really an issue on this job.
Click the link below to download the file included with this post.
Are you going to be doing the install, and the warranty that goes with it, or are you just being asked for your opinion?
I won't be liable for the warranty. However, I'm being asked to make a decision based on a technical perspective.
My opinion at this point is as follows:
1) A balanced construction means pull force of faces is equal to and countered by core.
Yes or no?
I don't like the Type 1 at all. Those 7 mm faces are strong enough to create problems with the cross grain core. At 7mm thick the faces will be trying to expand and contract along the width of the board while the 7 mm thick core is trying to do the same in the opposite direction. Based upon my experience this is a recipe for failure......especially if this is for a on slab or non-climate controlled environment.
Of the other two I'm partial to the ply core. I think that adds greater stability than the solid core. The 4 mm faces are right on the edge of perhaps trying to expand/contract on their own but probably are not strong enough to overpower the adhesive attaching them to the core, and hence, remain stable and not be likely to end up with surface cracking.
I am not sure the wood flooring association guidelines permit a 7mm wear surface, but I could be wrong. A 4-5mm wear surface from Mirage can be re-sanded 4-5 times, so I don't see much benefit with the thicker option.
With 12" wide planks I would almost be leaning towards something with a built up core like Kahr's uses (see image).
You could probably reach out to Charles Peterson and ask his opinion. He wrote the book below. I have chatted with him before, and he is quite a good guy.
We have had the type 2 in my foyer for 21 years. Wear has been great. It is white oak veneer Lots of sports gear and luggage dropped on it over the years.
I followed the mfg’s install and added about another 1/8 around for expansion as I used to lay hardwood when younger.
It still looks good but could use a sanding. I used the mfgs cleaner and dressing as required. Never wet mopped or steamed it. That voids the warranty
It’s remained flat. My shop runs a lot of balanced panels in our work and any special veneered panels I bring in we spec balance with like species.
I have been in a few pissing matches over the years with vendors and wholesale clients that want what they want and I bill them twice when panels bow uncontrollably and peel off a wall.
I today’s market of mills pushing faster than ever for even core, proper balancing and acclimation (spread out) is imperative.