How to fix rotten plywood under kitchen sink?

[LorenClayton]

Hello

I'd like your advice on how to get rid of existing damaged plywood along the wall under the kitchen sink, and the best material to use as replacement. I'm guessing plywood? I'm after a budget but permanent fix. The water damage was long before I bought the house October last year, and there's no dampness there. I doubt I can do this myself if carpentry is involved unless you can recommend a fairly easy fix - I am a reasonable handyperson. Area is about 1.5 M long and around 65 cm high. Thank you. 

[AlanM52]

Hi @LorenClayton,

That looks like MDF.

You could simply do the art & craft cosmetic thing and cover that with something like this.

or this.

The job would be easier if you can remove the shelf on the left.

Just a observation... on the right looks like the side of that storage shelf was removed.

Cheers

[LorenClayton]

Thanks for that Allen. The second option looks good. I'll see how I go.

[JacobZ]

Hi @LorenClayton,

Unfortunately, because of how cabinets are constructed as a whole unit and then installed against walls, removing and replacing the back piece wouldn't exactly be easy, as it would need to move backwards away from the side walls of the cabinet, which may not be possible if they are hard up againast the wall. You'd also have to remove the pipes and shelving to get the backing piece out, then mount timbers around the perimeter of the cabinet to attach a new backing piece to. I'd be happy to assist with this if you'd like to give it a try, but it sounds like you are looking for a simpler solution.

Painting is a fairly simple task that doesn't require any carpentry. While it doesn't look like it is in fantastic shape, it doesn't actually look like it has been significantly weakened, which makes me think simply priming and painting over it could be a good option.

If you wanted to give this a try, I would use a paint scraper to remove the flaky bits, give it a sand with a sanding sponge, clean it up with some sugar soap, then prime and paint.

This could be a simple way to make it look good again.

Allow me to tag @Noyade, @Dave-1 and @TedBear to see if they have any ideas.

Let me know what you think.

Jacob

[TedBear]

Hi @LorenClayton , the water damage looks like it may have been from the sink overflowing. If so, it was a one-of event. Is removing the back necessary? If so, I'd use a Multi-tool saw, but if it's a cosmetic repair you're after, best leave it in place. The easiest material to fit there and give an acceptable result would be thin Tongue and Groove boards. (Not floor boards .)

You can remove the S trap, then lift them over one at a time, once cut to length. Then screw or glue each to the existing back. They will be easy to work with and to cut to size to fit around the existing shelf. Then paint if/as required.

Screwing will be easiest especially if you pre-drill the holes in the boards... not too close to the edges or else you'll have trouble getting a driver in there. 

The suggested Corflute could also work as it flexible, so you may be able to flex it around the pipe, then cut a slot for that shelf. Disadvantage is that you can see through it when it is up against a surface, so you'd want to then cover it with something to make it look good.

[Dave-1]

Good Morning @LorenClayton 

Having something you see every time you open the cupboards would niggle away at me

I actually was thinking along teh lines of @AlanM52 and @JacobZ 

I would go with some thin plywood, cut it out in either two or three segmants. 

Remove the shelves gently (you can put them back later if you want)

Then smooth off the old material as @JacobZ has suggested.

Glue the segmants to the rear and then paint.

The reason why I was thinking 3 segmants was because working under a kitchen sink is always a pain,the flexibable plywood (3mm) can be bent easier if needed. Its only light but will make a solid looking backing.

Dave

[LorenClayton]

Thanks everyone. A carpenter did this job in an hour & a 1/2 for $200 including the panels. He cut 2 pieces of melamine coated chipboard so that the top piece fit into place about the ledges (so nothing had to be removed) and the bottom piece just went across. There is a small horizontal visible seam where these join. The 2 pieces were long enough that it covered all of the damaged wall. It took a bit of time to manoeuvre the top piece in place but I'm very pleased with how it looks. So nothing had to be removed. He tacked the 2 pieces to the damaged wall behind as I asked him to (not sure whether or not he glued).

[LorenClayton]

Thanks TedBear. This was actually what the carpenter did, using melamine chipboard. It looks good.

[Jason]

Glad you got it sorted @LorenClayton. Please don't hesitate to post anytime you need a hand. 

Jason