Pre Bathroom Install Issues

[patchworks]

I am in the very early stages of a full bathroom refurbishment.

Before placing an order with an online distributor, I wanted to check the state of the floor to ascertain whether a slimline shower tray would be okay or whether I would need one with a plinth to bring the height up.

I removed the first floor tile, only to discover that the wooden base layer (chipboard) that the floor tiles sit on is completely rotten. I dug a little deeper, removed a few more tiles and everything is pretty rotten under there.

http://media.diynot.com/209000_208579_72224_98338867_thumb.jpg

I've felt around under the bath where the taps and waste pipe are and even the bricks are damp and crumbly.

http://media.diynot.com/209000_208579_72225_31563332_thumb.jpg

I'm on the first floor of a maisonette. Downstairs have not said anything to me so I assume its not a problem down there, but I will ask when I next see them.

I'm also slightly confused as half the floor seems to be concrete and the other half is floor boards, is this usual?

I'm wondering if this is just 'one of those things' or if this is a bad install that I've inherited; If bad install what should I look out for to make sure this leak doesn't happen again?

If anyone has any advice I'd be extremely grateful

 

[Norcon]

Setting the tray on a plinth will depend on where the drain is located.

 

[longdogs]

A shower should not be sited on a chipboard floor as any dampness and the chipboard will blow and crumble. I have often come across half concrete and half boarded floors but not sure of the reason.

I think you need to remove as much of the damaged floor as possible and refit. otherwise you could be in for trouble after fitting your new bathroom. Under the shower or bath should be marine ply.

 

[GavThePlumber]

Rip it all out.

 

[Blagard]

As posted by others the chipboard floor needs to be removed and if you plan on having a tiled floor, replace it with exterior quality plywood as a minimum, marine ply is another stage better but should not be necessary unless you plan on having leaks built in!

As for the concrete bit - Is the property a conversion of an old house. If so the concrete may be where an old hearth or chimney breast was, but otherwise I can't think why it should be mixed.

Without seeing more it may just be the long term effect of small leaks, but would suspect the installation was bad.

 

[chantelle]

You need to learn the basics of waste drainage and how yours works before worrying about floorboards/chipboard.Which way do your rafters run? fit a slimline if you have the fall beneath to allow water to drain.Your first concern is will it empty after i fit it? Tarting up the bits on show comes later.Seen beautiful shower installations that stink like old farts because numpty Joe thinks water walks from the shower waste to nearest outlet, then boxes/tiles in the lot without regard for access in case it all goes t@its up..which is usually the case when you don`t have a clue...

 

[patchworks]

Update: Thanks for all responses. I have done further investigation, removing bath panel and a few more tiles.

The corner of the bathroom (1.1 x1.1 metres) is concrete and the remaining area seems to be floor boards as I expected.

Shower is going where the floorboards are rather than the where the concrete is. I've checked and i'll be able to get shower waste out with a good drop so the water runs away.

Have encountered another potential problem in the middle of this though. On the external wall to where the bath is, the bricks are extremely wet looking. (can't investigate this at present as access would be through neighbours garden who are currently away).

The wet looking bricks are in a Quadrant shape; starting where the shower head is and then arcing away before hitting the floor line, leaving me convinced it cant be anything else.

Due to the layout of the flat, it's not really an obvious thing to spot and therefore have no idea how long it has been like that.

Inside the bathroom, there have been no tell tale signs of any issues. I would have thought the tiles would have started to loosen or come away, but they are all pretty solid.

Has anyone had any experience of this?

Bathroom bits and pieces aren't arriving for another 3-4 weeks, so I've potentially got some time on this (hopefully)

 

[longdogs]

unless you plan on having leaks built in.