Roof Leak - can’t figure out what it could be :(

Newuser0

I’m hoping I can get to the bottom of it, otherwise I’ll be having sleepless nights lol

Doozergirl

Where is the vent in the room for the chimney?  

stuart45

The problem could be that you have very tall, exposed stacks and no trays built into them. Nowadays at least one tray is put in above the roof line. https://www.bing.com/videos/search?q=just+lead+lead+tray+video&docid=608052938492347332&mid=CE4133CF55D842F1E778CE4133CF55D842F1E778&view=detail&FORM=VIRE
On an external breast you also need a tray lower down when the flue liner crosses the cavity, because at that point the cavity is lost. 
It looks like there is 2 flues in that stack, and the upper floor one looks unused, so that one won't be drying out as well as the other one.
Your property may not have flue liners, as it looks like it was built before the mid 60's.

Newuser0

Ahh I’ve never heard or seen these flu trays before. I’ll speak to the roofer about it.

in terms of a vent, as you pointed out, there are two flues as there used to be fireplaces in the two bedrooms from the marks on the floorboards. I take it I need to install vents in to that flue? Is there a way of doing that without it affecting the flue in use? 

Is this vent added by a roofer or a fireplace specialist?

stuart45

Tray are fitted in modern chimneys with flue liners, as the lead is dressed around the liner. Years ago the trays were probably not needed as fires were often lit first thing in the morning and kept going all day long. Nowadays they tend to be used a lot less.
Can't find a link to a lower tray, but this poor drawing might give you an idea about the liner crossing the cavity. 
It probably does not apply to you, so don't worry. Remember that roofers don't build chimneys so sometimes don't understand the construction of an external chimney breast. They are less efficient as they are more exposed.
Putting in a vent is a simple job for most trademen/handymen. It won't effect the other flue.

Doozergirl

As Stuart says, the vents are easy and can be done by anyone, but I can't help thinking that opening them up and using them as fireplaces is often the best course of action!   They help ventilate rooms, not just the chimney.  

Jeepers_Creepers

Hi Newuser.

Where is that new stain in relation to the chimney stack?

Where is that bedroom's fireplace located - I can't see an internal breast in your photos, unless that stain is a close-up and it's on the breast?

What can you see when you go in to the loft, crawl on yer belly like an animal and shine a big bright torch at the internal part of the stack? 

Anyhoo, I think some things we can say are, I don't think you have any claim or obligation from the first roofer, provided the work he did with the flashings etc was good; I think it's pretty clear that he did fix the initial problem. No-one knows if this new stain is related in any way to the old issues - they could be quite separate.

I think it's time for a second roofer's opinion. Ideally you want someone local and familiar with these types of house - do you know any neighbs who have had roof work carried out recently? If so, ask them. 

Either you or the roofer also needs to try and look at that stack in the loft space - that should surely be a good pointer? 

The original stain was at floor level, so that suggests (I think) water that's been making its way down between the flue liner (surely it has clay pipes at least?) and the surrounding stack - often that gap is filled with 'stuff'. I mean, the water came down a good way before finding an escape route out near your floor level. But that seems to have been fixed by the roofer.

The new stain looks slight, and by the way it comes through at the ceiling height, would suggest it's being formed nearer the outside of the stack (or that you have faulty flashing around the stack base - but that's all new.

See what the new roofer suggests, but by a process of elimination the most obvious candidate is as mentioned earlier - that's a large area of exposed brickwork that's catching driving rain. If it gets through the pointing to any great depth, fair chance it can make its way down past the inside of the lead flashing (which usually only goes in to around 1/3rd depth)  before allowing the brickwork inside the loft to become damp as it comes back out to the surface. Unless your pointing is in very good order, some water will get in past the bricks and could easily also get down past the flashing. 

This is all guesswork, of course, but if the roofer can find no other credible cause, I fear you may need to bite the bullet and have the stack repointed. Think of it as an investment... I would use an experienced 'wet' builder for this and not a roofer, unless the latter can demonstrate he has the skills. Pointing is not exactly a highly-skilled job (I know I know - it is skilled when done properly) , but what is vital is that it's done to a good depth, to a well-cleaned out gap and with the correct mortar mix for these bricks. And, of course, that it looks good - these are really nice stacks.  Consider the best finish to shrug off water - that's the key requirement here, I'd suggest: https://theconstructor.org/building/pointing-brickwork-construction/11290/

Newuser0

Thank you for all the info guys! 

The house was built in the 1930’s so definitely no liner.

In terms of the stains, here’s some images that may help.

The red circles are the new damp spots. The green circle was were the old wet patch was, which I feel is now dry.

the purple line Is approx where the external chimney is running up.


Externally, the red circles showing approx new stains location. Green line showing the master bedroom size and purple to reflect the interior pic.



I’ll go in to the loft and have a good look when I’m off and see if I can see anything. However, before the work was carried out for flashing, soakers etc the roofer had a look in the loft and said it was bone dry

Thank you for all the help again guys! 

Also, can anyone recommend a good roofer or builder for this job in Birmingham?

neilmcl

Newuser0 said:

I thought maybe a new comment on a old thread doesn’t bump it up, and had no replies so thought it might be better to start a new thread 

Please read the forum rules regarding starting unnecessary multiple threads. It's there for a reason.

Doozergirl

I can recommend you a roofer.  Which bit if Brum? 

I think you should vent it first.   Is it fresh plaster? 

It could be a bit of condensation.  It's on a join which is relatively protected from the rain, but it could easily be a thermal bridge.