Foam under the decking, pros and cons...

[bassboy1]

One reason bags of foam would be better than bags of air is bags of foam won't be affected if punctured.

Now we're back to square one - the bags get punctured, and the foam gets waterlogged, and you have the concrete blocks that PSG mentioned.

I'm not trying to be critical here - just furthering an interesting, all the while constructive, debate.

 

[PSG-1]

I used the blue board insulation. I liked it because its easy to cut and fit to the shape of the boat. The other board insulation probably is good for the same reasons. It has made the deck sturdier and more quiet.

Correct. The blue, or the pink foam board is what you should use.

You can also use the white styrofoam 'bead board' but it is more likely to break apart into those annoying little styrofoam balls, and it's not nearly as tough as the blue or pink foam board.

Typically, 1 & 1/2" board will fit underneath an inner deck, if the ribs are made of square tubing.

If they are the older, round type of ribs, 3/4" is probably going to be a better fit.

 

[MNHunter505]

Anybody use 1/2" plywood for decking and have good results or is it standard to use 3/4". trying to save some weight. Thanks.

 

[PSG-1]

I would think that if you use the correct thickness of foam board, where it's flush with the top of the ribs, you could definitely use 1/2" plywood and it would be adequately supported.

Same as with using 1/16" aluminum sheet for the floor with foam underneath, as opposed to using 1/8" with no foam underneath to support it.

 

[MNHunter505]

I would think that if you use the correct thickness of foam board, where it's flush with the top of the ribs, you could definitely use 1/2" plywood and it would be adequately supported.

Same as with using 1/16" aluminum sheet for the floor with foam underneath, as opposed to using 1/8" with no foam underneath to support it.

Yea, that is what I was thinking! I might have to give that a try...

 

[Butthead]

Pool noodles on my boat!

aaahh, I like that! Hey, how are you going to attach the wood to your ribs?

I just put a few screws through the wood into each rib and did a staggered pattern down the length.

x x x x x
.x x x x
x x x x x
.x x x x
x x x x x

It may have been overkill, but I'd rather over do it then have to fix it later.

 

[MNHunter505]

Pool noodles on my boat!

aaahh, I like that! Hey, how are you going to attach the wood to your ribs?

I just put a few screws through the wood into each rib and did a staggered pattern down the length.

x x x x x
x x x x
x x x x x
x x x x
x x x x x

It may have been overkill, but I'd rather over do it then have to fix it later.

I read a post by someone who put industrial velcro on the top of the ribs and then set his floor down. That way it can be removed easily. I am thinking of giving it a try.

 

[Butthead]

I read a post by someone who put industrial velcro on the top of the ribs and then set his floor down. That way it can be removed easily. I am thinking of giving it a try.

That's definitely an option if you want it easily removable. I think the regular black adhesive backed Velcro is rated at 2lbs of holding force per inch so I wouldn't recommend putting it all the way across and on every rib or else it could be a little challenging to pull it up when needed.

 

[MNHunter505]

I read a post by someone who put industrial velcro on the top of the ribs and then set his floor down. That way it can be removed easily. I am thinking of giving it a try.

That's definitely an option if you want it easily removable. I think the regular black adhesive backed Velcro is rated at 2lbs of holding force per inch so I wouldn't recommend putting it all the way across and on every rib or else it could be a little challenging to pull it up when needed.

Very true, I will have to stagger 3in lengths across the ribs. Here is a question, how are guys securing there alum framing to the boat? I know they pop rivot the pieces into the belly/bottom ribs but what about the sides of the framing that touch the inside of the boat walls...?
https://www.tinboats.net/forum/viewtopic.php?f=21&t=13160&start=45

 

[xbacksideslider]

Anybody use 1/2" plywood for decking and have good results or is it standard to use 3/4". trying to save some weight. Thanks.

I used 1/2" for my casting deck and 1/8" over styrofoam board for my floors.

As for the 1/8", I punched a hole in it with the gear shift lever when I dropped the outboard down onto it too quickly.

 

[MNHunter505]

Anybody use 1/2" plywood for decking and have good results or is it standard to use 3/4". trying to save some weight. Thanks.

I used 1/2" for my casting deck and 1/8" over styrofoam board for my floors.

As for the 1/8", I punched a hole in it with the gear shift lever when I dropped the outboard down onto it too quickly.

Wow, that stinks! 1/8" seems a little thin for a deck...I think I will stick with 1/2" on all flooring.

 

[xbacksideslider]

Yep, dented/punched it, but it's 30 or 40 pounds lighter than 1/2" and the floor pieces are one piece, easily removable to a clean and dry inner hull.