mdf versus marine ply

[ceramic man]

Hello

Can anyone tell me which of the following is best to to resist mositure for use in a bathroom (not in or near the shower/bath, not to be splashed with water) and how they compare price-wise, approximately for a sheet around 1220x2500mm:

Marine Ply
Moisture Resistant MDF
Exterior MDF

many thanks

 

[xerxes]

Standard board sizes are 2440 x 1220; specialist marine ply comes in 2500 x 1220.

You can do some rough price comparisons here, where prices are based on pallet quantities.

True marine ply is completely over the top for this application.

You haven't listed WBP plywood and might consider using this. Standard MDF soaks up water like a sponge. Perhaps others can comment on exactly how moisture resistant MR MDF is.

 

[Jasonb]

As said above, marine ply is OTT, WBP ply will be suitableand cost a lot less.

MR MDF will also be suitable in the conditions you are using it in. Untreated it will remain stable with chnges in humidity, however if it is allowed to become soaking wet it will swell by at least 50% of its thickness.

EXT MDF will again be suitable for your use, if it is to withstand soaking it needs to be sealed on all surfaces otherwise it can swell a bit.

All of these wood based products will move a small amount with changes in humidity and this may affect the bond of your tiles/adhesive that is why I suggested Wedi board which is innert.

Another thing with the wood based boards is that unless you seal the back of the unsupported boards the moisture in the adhesive being applied to one side only may cause the boards to cup.

Have a look at this site it gives board prices based on the quantity you order.

Jason

 

[ceramic man]

thanks for the great advice, here and elsewhere and the link to the site -

Now, yet another question (I don't want to appear too 'fussy' I just want to do a safe and professional job): is there significant difference between caber, medite and MDF? on this link:

http://www.richardrussell.co.uk/view_stock.cfm?sec=3

or will all be equally good for my needs?

Thanks

 

[Jasonb]

Both Caber and Medite are well known brands and both companies products are very good, I tend to prefer Caber but there's not much in it.

The general purpose MDF is just cheap contract grade and I would not use it.

Jason

 

[ceramic man]

thanks, very good info