Plywood or MDF?

16 Sep 2007
Reaction score
United Kingdom
I need to replace the wood behind my bathroom sink and toilet that boxes in the pipework at floor level.

The original was Plywood but I was thinking of using MDF instead since it has a smooth surface and will be easier to paint to a nice finish.

I presume there are no advantages to using Plywood over MDF in this situation?

Sponsored Links
Plywood is a lot more moisture resistant than standard MDF, but no better than MR-MDF (moisture resistant MDF - often green coloured or with a green core). I'd go with MR-MDF over the other two
MR mdf is very expensive, you could use standard mdf and moisture resistant acrylic paint, or even gloss.

MR mdf is very expensive, you could use standard mdf and moisture resistant acrylic paint, or even gloss.
My experience with that is that sooner or later the water gets through the finish and causes the MDF to swell. That's why window boards are almost always MR-MDF. MR is still cheaper than plywood, too
Last edited:
Sponsored Links
Use ply.

Don't ever consider using MDF anywhere near moisture. Better still, don't ever consider using MDF for anything. It is soulless. The cheap cheddar from Tesco has more character and is just as easy to cut.

Yes, MDF is lovely and smooth. And there are a miriad of ways of sealing the edges. None of them work. MDF even absorbs the solvent in non water based paints.
8Yes, use ply, you'll always see the grain and you'll never hide be able to hide the horrible edges unless you lip it with hardwood, and then you'll find that the lipping almost always shows through the paintwork. In bathrooms, kitchens, etc you should always use an oil-based paint in any case.

As it happens the pipe boxing around the soil pipe in our bathroom was done in 12mm MR-MDF over 2 x 1in softwood framing about 20 years ago, primed and painted in oil-based and it still hasn't swelled... but there's still time before I move the bathroom next year ;)
Last edited:
Why not use use Shower Panelimg? There are choices of MR-MDF, Ply and semi-ridgid foam plastic cored sheets.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local