what about concrete backerboard instead of wood for deck?

Eute

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Feb 17, 2010
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Has any one tried using the concrete backer board as a water proof flooring Material? it dont weigh any more then plywood, used all the time in tile shower installation.
 

benjh1028

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Re: what about concrete backerboard instead of wood for deck?

Its not a structural product - its placed on top of plywood on horizontal surfaces.

Ben
 

Eute

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Re: what about concrete backerboard instead of wood for deck?

hmm never seen them use plywood behind it. Im a new constrution plumber and never seen that done that way i always see them just nail it to wall.
 

Eute

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Re: what about concrete backerboard instead of wood for deck?

and another thought is why not use the metel studs instead of 2x4 wood they now use to build with? they dont rust, made of tin i believe.
 

lrcustom

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Re: what about concrete backerboard instead of wood for deck?

Yes it has great water resistance but it has no structure of it's own. Used to form stringers or used as a floor it will just crumble. Plywood has structure in all three directions no matter which way it's cut or positioned in a boat. Then glassing ply with resin and cloth, mat or... it becomes even stronger. Backer board weighs the same as pressure Treated Ply wood (PT) but a good exterior non PT plywood weighs less. Then there is exterior glue hardwood (not oak) cabinet plys (7+ layer) are even lighter. There is plenty of advice on this subject here and new idea are great but sometimes what has been working is still the best way to go. It's proven so you can trust it.

Hope this helps.
 

Eute

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Re: what about concrete backerboard instead of wood for deck?

thanks Ircustom very informative information. I was just wondering with all the rotten wood post i read why put something back in that is just going to rot again
 

lrcustom

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Re: what about concrete backerboard instead of wood for deck?

Eute,
The hope is to do a very good job rebuilding our boats better than they were. The manufactures build fast and as low cost as possible IE: the wood rots because it's not taken care of. When we rebuild we have the opportunity to take our time to do a very good job. When we are done not only do we feel good because we built it but with great pride we can enjoy our craftsmanship and skill has we cast a lure next to that lilly pad or yank that skier out of the water. That's fun with a capital F.
 

seamorewaterVIP

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Re: what about concrete backerboard instead of wood for deck?

my 02 worth backer board is designed to add structural integrity to a sub floor to prevent flexing movements that could break tile or grout. if you try to span say stringers w/o sub floor the backer board will break. So cover your plywood with resin and leave the backer board for tile projects.
 

109jb

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Re: what about concrete backerboard instead of wood for deck?

hmm never seen them use plywood behind it. Im a new constrution plumber and never seen that done that way i always see them just nail it to wall.

No they don't put anything behind it when used on a wall. They also don't put anything behind 1/2" drywall when used on a wall but would you use 1/2" drywall instead of plywood on the floor of a house?????
 

109jb

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Re: what about concrete backerboard instead of wood for deck?

and another thought is why not use the metel studs instead of 2x4 wood they now use to build with? they dont rust, made of tin i believe.

They are galvanized steel and are fine for walls in a building, But have you ever seen one used as a structural support like a floor joist? Also, how would you attach them to a hull?
 

reelfishin

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Re: what about concrete backerboard instead of wood for deck?

I think using backer board would be right up there with the Thunderbird trihull I bought last year for it's motor, the guy screwed down OSB for a new deck, over top of what was left of the old deck, troweled the seams and rounded the edges with mortar, then poured masonry floor leveler over the wood, then glued down flowered Armstrong Linoleum. I guess he did kitchen or bathroom floors for a living. The boat was so heavy by the time he was done the spashwell would fill with water with the boat empty. I borrowed a jack hammer to bust up the deck just to lighten it up enough to scrap it.
 

dockwrecker

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Re: what about concrete backerboard instead of wood for deck?

They are galvanized steel and are fine for walls in a building, But have you ever seen one used as a structural support like a floor joist? Also, how would you attach them to a hull?

Yup, 2x8 16 ga.studs back to back w/ 5/8 ply over it. Lots of shed manufacturers do it. Termites don't like steel...
 

lckstckn2smknbrls

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Re: what about concrete backerboard instead of wood for deck?

They make a non-concrete backer for shower and tubs. That might or might not work for a floor. I think it only comes as 32"x48" pieces.
 

Eute

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Re: what about concrete backerboard instead of wood for deck?

Thanks very good answers i didn't take in consideration. :)
but they do use the metal studs as load bearing walls and floor joist, the 20 gage ones which weigh about the same if not less then wood ones.
Also wouldn't you attach those the same way as you do wood?
Even doubled up 16 gage would still weigh a fraction of what wood would
 

89nissanbassboat

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Re: what about concrete backerboard instead of wood for deck?

I was at Lowe's today and was looking at the 1/4" Hardie board for sawfit material...very smooth surface on both side...it weighs about double that of the same material in wood...they claim it is water and moisture resistant and will not mildew...it's about 22 bucks a 4X8 sheet...I tried to bend the stuff but it is very rigid and looks like it might be strong enough for deck material...have you seen this stuff Eute?
 

seamorewaterVIP

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Re: what about concrete backerboard instead of wood for deck?

I was at Lowe's today and was looking at the 1/4" Hardie board for sawfit material...very smooth surface on both side...it weighs about double that of the same material in wood...they claim it is water and moisture resistant and will not mildew...it's about 22 bucks a 4X8 sheet...I tried to bend the stuff but it is very rigid and looks like it might be strong enough for deck material...have you seen this stuff Eute?

it will still fracture under foot w/o sub structure. I dont think it is a good idea to use it. not only do you have the weight of the hardi board but you have to support it some how so you will end up saving money just using good quality plywood and covering it in resin. and you will be done quicker. I am new to boating but I am by no means new to building stuff. ( many years of working in the construction industry) if you want concrete like substance then look at seabond or somethin like it. Mick used it on his Arkansas traveler thread go take a look.

Go to the lumber yard and spring for 2-2x4s and a sheet of hardi put the 2xs on the floor 4"side up 24" to 30"s apart lay the hardi over the 2xs and standon the hardi in between the 2x4s then jump as high as you can and land on it (this is essentially what happen when you hit some one elses wake) let us know what happens?

there may also be issues getting the resin to stick to it

or Give it a try in the boat but before you look at my tag line
 
Last edited:

marine4003

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Feb 3, 2008
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Re: what about concrete backerboard instead of wood for deck?

I was at Lowe's today and was looking at the 1/4" Hardie board for sawfit material...very smooth surface on both side...it weighs about double that of the same material in wood...they claim it is water and moisture resistant and will not mildew...it's about 22 bucks a 4X8 sheet...I tried to bend the stuff but it is very rigid and looks like it might be strong enough for deck material...have you seen this stuff Eute?

You can use cement backer as the floor,but be sure to encase it in plenty of glass,boats are made from ferro cement,these are the problems..weight-structural integrity-and fastening ability.foam board has also been used,again with plenty of glass. wood is more common because its easier to cut and shape to stringer and bulkhead applications.everything on a boat moves,bends..flex's. If all the components move in unison or at least have some flexibility it works,but if one major component is rigid..that's where its likely to fail.
 

Eute

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Feb 17, 2010
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Re: what about concrete backerboard instead of wood for deck?

yes i have heard of the hardi board and i might be thinking of it when i mention the concrete backer.
i think i can see Seamore ans Marine's point. Houses dont bounce off wakes and twist and flex (unless you live in Cali, lol).
I still think the metal stud might work as opposed to wood, just not sure if resin will bond to it like they said.
 

oldmanwaz

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Mar 20, 2010
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Re: what about concrete backerboard instead of wood for deck?

why wouldnt you use Starboard products?
 

F14CRAZY

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Re: what about concrete backerboard instead of wood for deck?

I think using backer board would be right up there with the Thunderbird trihull I bought last year for it's motor, the guy screwed down OSB for a new deck, over top of what was left of the old deck, troweled the seams and rounded the edges with mortar, then poured masonry floor leveler over the wood, then glued down flowered Armstrong Linoleum. I guess he did kitchen or bathroom floors for a living. The boat was so heavy by the time he was done the spashwell would fill with water with the boat empty. I borrowed a jack hammer to bust up the deck just to lighten it up enough to scrap it.

I had to literally laugh out loud at reading this :D
 
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