Joists rotted in bathroom, advice please

happyhero

Hi I am helping my friend sort out his bathroom (I am ex-building services so broad-ish skills). He cannot afford much, but wants to sort things out. He lives on the 1st floor in a flat which is actually built like a fairly typical house ie floorboards, lath and plaster ceilings, cavity wall etc, so presumably it was once a house and is now converted into flats.

Anyway his bath was fitted with a gap at the outside wall end (this is also the tap and waste end), this gap was filled with a batten and siliconed and leaked. This was done because there was a pipe in the way going up the wall. The result was that there was damage to the flat below and apparently this has been going on for a while.

I had a look at it all and found he has 2"x7" joists, one of which is badly rotted in the bottom inch or so for about a foot and that bit goes into the inner wall, plus another joist next to this one is not too great so could do with some attention. A few of the floorboards are rotten in this area with the result I can crumble them in my hand and one bath leg is actually floating in mid air with no floor under it, where the boards are so bad. The bath is one of those pressed steel ones ( hope I have that right, its metal cheap type basically).

He has also got some new taps to fit and due to it being a very small bathroom and the toilet being in the way, I think it best to remove the bath and repair the floor properly first, and this will enable us to connect the taps more easily too. Then we could deal with the pipe up the wall so its in the wall and we can fit the bath right up to the wall withoput a batten to leak etc, ie a much neater job.

Question is how would you go about this repair, ie joist is rotten into wall (which looks like brick as far as I can tell so far), would you join another one to it and channel the wall so it goes into the wall for support or how would you do it?

If I did this splint type job, what would be the correct method to join the joists, ie big screws, coach bolts or nut and bolt etc?

Rather than channel into the wall is there a bracket I should consider using (only problem with this idea depending how it fixes is the damaged joist is right under the bit of wall that has all the wastes going out of it), got any ideas here?

Lastly if I channeled the wall, how would I insure the joist was supporting the floor and that the channel was not too big, my guess is you make it bigger and then put cement in and rest it on that, is that right and if so could I use quick setting cement etc?

Any help appreciated, as I say my friend does not have too much money but wants to do it well.

olias

I agree that this needs doing properly rather than a bodge job.

I would ensure that all trace of damp is gone by drying the area out thouroughly before any work, then hack away as much of the rotted wood as you can. Also then treat the area in case there are any fungus/wet rot spores present.

Other than that, you seem spot on. I would attach the 'splint', using coach bolts, and preferably channel it into the wall (should be easy enough by removing a brick or using an angle grinder and/or cold chisel to hack a recess. As you say, the problem with a joist hanger, is if you have pipework above which will get in the way of fixing the hanger. You would be better off making good with just an ordinary mortar mix and leaving it enough time to 'go off'.

One word of warning, The flat below is likely to have a (fairly brittle) lathe and plaster ceiling, so and banging about etc to the joists may well result in some damage to their ceiling which you will have to make good! Also, any leaks, however small, as you alter pipework etc, may well soak through their ceiling as well needing remedial work!

Olias

Olias

Errata

Sounds pretty grim with a chance of it getting worse if it isn't fixed properly. I think he needs to claim on his buildings insurance and get the professionals in.

Fire_Fox

Errata wrote: »

Sounds pretty grim with a chance of it getting worse if it isn't fixed properly. I think he needs to claim on his buildings insurance and get the professionals in.

I agree with this: if there is a management company and communal buildings insurance they should be involved, as he may have problems selling later if structural work was carried out without permission. If he is a leaseholder not a freeholder you may be altering structures that don't technically belong to your friend. You can always help out with the plumbing and decorating once the structure is sound.