Kitchen Design/Remodeling/Counter top base


I am currently working on replacing my counter tops in my kitchen. I plan on making Oak counter tops out of reclaimed wood (1x6)  What should I use for the base (needs to be replaced, POs used particle board for the original tile counter top and it has A LOT of water damage -- my sink is falling through the counter top).What should I use for the base (underlay)   Is OSB OK?  Or should I go with plywood?  1/2" or 3/4"?

Thanks in advance.


Hi Nick, thank you for your question.  I should be able to help you with that.

That oak countertop should be really nice - reclaimed wood is very popular right now.  You have plenty of options for your C/T base material, but would probably stick with 3/4" thickness to start.  Assuming your 1x6 is really 3/4" thick, than a 3/4" base would give you the industry standard 1 1/2" final product.  Even if your oak is closer to 1", a little bit thicker is better than a little bit thinner.

You stated that you had a lot of water damage to the previous countertop that was made with a particle board base.  Particle board is a great countertop substrate and is the material recommended for laminate countertops, but not tile.  Laminate is not a porous material - therefore, if the sink is caulked properly and the faucet is not leaking, your particle board should last a lifetime.  With a tile countertop - this is not the case.  Even if the sink and faucet are perfect (zero leaks, properly caulked), the grout is still porous and can allow moisture to pass through under even the best of circumstances.  Add in a small faucet leak or lots of splashing around the sink, and that water will find a way through.  The grout should always be sealed, but the quality of sealers and time it lasts can vary greatly.  For that reason, I only recommend using marine grade plywood as the base material under tile.

On to a wood countertop.  With a wood countertop, there is less likelihood that water will get to the substrate.  The wood itself will probably absorb the moisture before it ever gets that far.  That isn't a good scenario either, so you will have to take great care in getting a good finish/sealer on your wood that protects the wood from water damage altogether.  Wood finishing materials and techniques are out of my area, so I would recommend doing more research on that in your area and maybe even speaking to your local furniture makers for their suggestions.  Try to find a finish that will allow you to maintain it as the years go by.  I have seen wood that has been sealed with so many layers of urethane that when it chipped, the urethane cracked and peeled off.  That will be a nightmare to maintain longterm.  Butcher block countertops often use a sealer that penetrates the wood and does an amazing job of maintaining the texture of the wood as well as protect it from most spills.  The product I've used before is called "The Good Stuff", and should be available online or from your local dealer.  You will probably need to maintain the surface once or twice a year, but it is worth it compared to other products out there.

With all of the above information taken into account - I would STILL recommend a substrate better that particle board or regular plywood.  If your lumberyard has a product called Advantech, that is a great choice.  In my local area, it is what the high-end custom home builders are using on their sub-floors.  I've seen that sub-floor after a rainstorm in homes without the roofing on, and when dry, it looks like it was never wet to begin with.  You could also go with the marine grade plywood if you want to be extra careful.  But check the pricing and availability.  You asked about OSB, and in my experience, because of all the chips and glue used in making that product, I would suggest something else.  When attaching your oak to an OSB substrate, there is no consistency in where you staple (or nail?) the oak.  

With as much time and effort you are going to be putting into this oak countertop, I'd spend a few extra dollars on the best substrate you can use.  Sealing the wood will keep the moisture from the sub-floor, but you will still have to contend with the occasional faucet leak that no one ever plans on happening.  

Sorry for my long-winded response for what should have been a simple answer.  But I get paid by the word, soooo... just kidding.  I hope this helps and best of luck on your new oak countertops.  Maybe you could send me a picture when its all finished.

Thanks again,
- Scott  

Kitchen Design/Remodeling

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Scott A.


I can answer questions regarding the kitchen & bath design process. My specialty is problem solving and advising clients about realistic expectations and proper procedures. Please feel free to use this forum for fact gathering and overall questions about the remodeling process and how to get started. I take special pride in solving unique design issues (issues unrelated to interior design).


I am the general manager of a kitchen & bath design showroom that offers complete sales, design, and installation services. Our products include cabinets, countertops, flooring, and appliances.

I have been working in the field of kitchen & bath design since receiving my B.S. degree in Architecture in 1992. I also own my own residential home design company, and have been designing custom homes for local builders since 1993.

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