Tile underlay plywood

Please see our tutorials and FAQ before posting.
Post Reply
Frequent Poster
Frequent Poster
Posts: 31
Joined: Fri Jan 18, 2019 7:44 am
Location: Wilmington NC

Tile underlay plywood

Post by Ncsharker » Thu Feb 28, 2019 12:16 am

Hey guy.
So I looked up marine grade plywood. Then I looked up what makes it marine grade.

Well tile underlay plywood has the exact specs if not better and it’s only $13 a sheet.

Has anyone ever built a small boat with it??

Very Active Poster
Very Active Poster
Posts: 3670
Joined: Tue Jan 12, 2010 12:25 am

Re: Tile underlay plywood

Post by fallguy1000 » Thu Feb 28, 2019 12:33 am

you can try anything you want, but a 30 minute boil test is advised

measure a small piece of plywood for thickness
boil for 30 minutes
remove from heat and measure thickness
if the glue is failing or the part is dimensionally changed or badly warping, etc. it is not boat quality
My boat build is here -------->


* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 5578
Joined: Tue Aug 02, 2011 4:23 am
Location: Kasilof, Alaska

Re: Tile underlay plywood

Post by Fuzz » Thu Feb 28, 2019 1:41 am

The FS-14 calls for 4 sheets of 1/4 and three sheets of 3/8 plywood. Total cost for plywood about $480 plus shipping. If you go with some other plywood it will cost you $100-150 so you MIGHT save $330. But will you have true marine grade plywood with no voids in it? I would bet not. By the time you add in all the other costs of building plus your time it just seems to me like it would be penny wise and dollar foolish to go with suspect wood. But as was already said it is your boat and you get to make the choices. Either way start a build thread and post lots of pictures :D

Very Active Poster
Very Active Poster
Posts: 1197
Joined: Sat Nov 06, 2010 7:10 pm
Location: Lakeland

Re: Tile underlay plywood

Post by silentneko » Thu Feb 28, 2019 6:50 am

I built my first boat using underlaminate, 5mm if I recall. It did ok, but was not what I would consider quality. The only thing it has in common with marine ply is it uses waterproof glue. The plys are not really even thickness, with paper thin outer vaneers that make bonding an issue if your resin doesn't penetrate well. And the wood is pretty week stuff with plenty of voids. I'd be ok using it for a calm water rowing craft, but I wouldn't use it for a powered boat. For that I would stick with Merantti.
Built: 15ft Skiff, 16ft Skiff, Modified Cheap Canoe.....FS17 coming soon!

Post Reply

Who is online

Users browsing this forum: No registered users and 35 guests