Concrete Countertops on a Boat ?

[Deep6]

Hi everyone,

I recently took a course on doing concrete countertops and really like the way they look as well as the freedom allowed form wise. I am redoing my own counters in my house which is going well albeit messy, and started thinking about their applicability on a boat? Does anyone foresee any issues? The only ones I see upfront are maintenance in the marine environment (more frequent waxing) , weight and what I would suspect would be a higher chance for torsional strain which could lead to cracking? Anyone have any thoughts on this?
I know a bit of a bizarre thought... :P

[delmarrey]

I think I'd be worried about cracking unless you have a really really big fireplace.

[Zanshin]

Corian counters are found on boats, Corian has a density of 1.75g/cm3 and concrete is 2.3g/cm3 so about 35% heavier by volume and I suspect that concrete needs to be thicker than Corian for identical structural attributes. That is a lot of weight to add (above the waterline) to any size boat. Most boat countertops are simple shapes and need a high fiddle so I would think that any advantages that concrete countertops might have would be outweighed by the weight disadvantage.

[ozskipper]

Weight?

[waikikin]

Originally Posted by Zanshin

Most boat countertops are simple shapes and need a high fiddle

You could do like a street kerb for the fiddle & a driveway layback for wiping out

[MarkJ]

Should be fine on a ferro boat

[PAR]

Use a good bit more 'glass in the mix or cotton flock, plus the steel, the concrete will be fine. Also use a high strength cement.

[SkiprJohn]

Because of the weight I would not put them on my boat.
kind regards,

[swisscraft]

Originally Posted by Zanshin

Corian counters are found on boats, Corian has a density of 1.75g/cm3 and concrete is 2.3g/cm3 so about 35% heavier by volume and I suspect that concrete needs to be thicker than Corian for identical structural attributes. That is a lot of weight to add (above the waterline) to any size boat. Most boat countertops are simple shapes and need a high fiddle so I would think that any advantages that concrete countertops might have would be outweighed by the weight disadvantage.

Using this numbers it really depends how thick you have to make it...and the size of your galley :-)


1 m2 Corian countertop with 2cm would weight 34,4kg
1 m2 concrete 2cm thick would be 46kg


If you can stick with thin layer and you love that stuff - why not? You are now the expert after your course: Measure your countertop, and calculate - 10 - 20kg more or less should not be a problem - as long you do not use concrete everywhere....

I don not see that much an issue with cracks, usually a boat countertop is not that big...but again, depends on the boat size...

[Event_Horizon]

Something else you might need to consider is the supporting structure for the counter top. If you had the light wood counter tops before, the supporting structure may not be sturdy enough to anchor the concrete in heavy weather or for long periods of time. Additional modifications may be necessary.

[Shorty]

For them to have reasonable structural integrity, they need to be pretty thick which equals weight. The concrete counters I cast for my kitchen are 2-1/2" thick to accommodate the rebar & mesh. You could probably get by with just mesh but would still likely need 1-1/2".

[osirissail]

If you are up on the latest technology with concrete you fill find that rebar and mesh is not needed anymore. The high tech concrete is a mixture of fiberglass fibers and concrete and has the same strength or more when compared to the old rebar/mesh versions.
- - However, getting a good finish on the surface I presume would be very difficult. Cement is not very hard. If you are using a high aggregate mixture and grinding/polishing then you have the same problem of fracturing when the boat flexes.
- - Cultured Marble is really just colored epoxy poured into a mold to make counter-tops and sinks as a single piece. I had this done for my two heads and they are beautiful especially the integral sinks. And they are about 1/2" thick. Because they are poured epoxy they flex and do not crack. However you must allow buffer space around the pieces so they can expand and shrink with temperature and also boat bending/twisting.

[banyandah]

I had made a SS sink top with integral sink when rebuilding Banyandah and it is well worth the money. light weight, (supplied on 12mm ply) nearly bulletproof, looks good. Can even clean fish on it and put hot pans down on it.

Cruisers & Sailing Forums - banyandah's Album: BANYANDAH - the rebuild - Picture

Cruisers & Sailing Forums - banyandah's Album: BANYANDAH - the rebuild - Picture

I have a concrete boat and adding more weight with concrete tops seems over the top. BUT, if its made thin, like constructing a ferro boat, with multilayers of fine mesh, it could probably come down to 3/4". I made a 5,000 gallon water tank that thick 20 years ago and it still in use.

[rusky]

I have seen a challenger 36 with 1" marble counter top in the galley. It looked great and was made from off cuts from a house. Sureley concrete would be less dense than marble.

[witzgall]

You would have to pour the concrete with the boat on the hard, leveled perfectly?

Interesting idea, but unless you have a 30k lb+ boat, not a good use of carrying capacity.

Chris