possible rot in joists

[Sef1928172]

Hi,

We have recently purchased a house and one room had polystyrene ceiling tiles, which we have removed, along with the plasterboard ceiling, which we were going to replace. We have found that there are some questionable looking ceiling joints in one section, and these appear to be rotting.

From our survey, it was flagged that there is the remnants of a chimney stack on the roof above this area (the chimney breast has been removed), so my guess is that all of this is to support the stack, and that this may have had some water leakage over time, though it seems dry now.

So ultimately, my question is, how bad is this? Will we be able to replace the joists in the affected area, or would it potentially mean the entire ceiling will need to be replaced. Will this be a expensive job?

Any comments and expertise welcome.

Thanks

 

[datarebal]

is there a flat roof there too?

 

[Sef1928172]

Yes, This is beneath a flat roof

 

[Sef1928172]

Does anyone have any comments/suggestions on this before it get buried?

 

[JohnD]

poke the suspect timber with a large, flat-ended* screwdriver. it will sink into wood that is weakened by rot or worm.

How do you know the source of water has been repaired and the timber is now dry?

*nothing pointed or round, because the marks will look like insect bore-holes in any subsequent inspection.

 

[Sef1928172]

It just feels dry to the touch, which makes me assume the water ingress has been solved. This is a new property that we have just taken possession of so not really sure, but trying to make best guess.

Have poked a few joists with a flat head as you mentioned and there is some give but it is not terrible.

I will have a builder take a look and decide if we need to replace some of the more dodgy beams before we put a ceiling back up.