Boiler flue leaking into garage ontop of boiler.

[Tagged]

Hi all.

Having problems with my garage boiler flue leaking. Had problems with my garage roof leaking when I moved in, managed to sort them with cement sides and fitted a dry ridge myself.

The boiler flue goes straight up from my boiler out the top of the roof. It's badly fitted due to the lead flashing is split and the cowboys that fitted it, I noticed water dribbling down onto the boiler itself a whole back. I tried to repair this temporarily by using roofing and gutter sealant which seems to have done fairly well actually.

The tile ontop isnt sitting exactly flush with the rest, I haven't managed to get a lend of a grinder to cut this yet but thought it wasn't too far off where it needs to be. Following a video online by fixmyroof I took the tiles off and tried to see if there was anything obvious I could notice why it might be leaking and nothing apart from the flashing had sagged at the back so I straightened it up and put a piece of batten in to hold it there and a little cement to try and stop water running backwards hoped that might be it sorted as my fear was the water was running down the back of it and into the felt and thus into the flue.

Today its raining and still leaking so I've gone up to take a few snaps for you guys see if you can see what's causing the issue.

It's not torrential just an odd drop here and there, if I shine a torch up inside the felt underneath I can see its wet. Obviously this collar needs replaced but I don't want to do it until the summer time. I understand its a little hard to see up inside apologies.

I was going to replace it with this and just mold it to the tile again but would like to repair it for now. - https://www.screwfix.com/p/floplast...JCexXGw5sIOvN3k2rgsaArfNEALw_wcB&gclsrc=aw.ds

Any comments or advice welcome thank you.

Edit - Just been out to check inside again as the rain is quite heavy and seems to be slightly worse than I thought. The water SEEMS to be coming down the side facing the block wall so from the aerial point of view it would be facing away from the roof.

Can't understand where the water is coming from

 

[foxhole]

https://www.diy.com/departments/bos...EAQYASABEgKqV_D_BwE&gclsrc=aw.ds&storeId=1271

 

[Tagged]

https://www.diy.com/departments/bos...EAQYASABEgKqV_D_BwE&gclsrc=aw.ds&storeId=1271

Thanks for the reply.

Can you explain a bit about what to do or where to apply this? Around the outside or something?

 

[foxhole]

All over the junction of vent and roof.Outside

 

[Tagged]

All over the junction of vent and roof.Outside

Im guessing a proper fix is to actually replace it, I'm confused where the water is getting in though

 

[Nige F]

Hi all.

Having problems with my garage boiler flue leaking. Had problems with my garage roof leaking when I moved in, managed to sort them with cement sides and fitted a dry ridge myself.

T
I was going to replace it with this and just mold it to the tile again but would like to repair it for now. - https://www.screwfix.com/p/floplast...JCexXGw5sIOvN3k2rgsaArfNEALw_wcB&gclsrc=aw.ds

Any comments or advice welcome thank you.

That rubber flashing is designed for 110mm pipe - is yours bigger ? Just get a roll of denso and wrap it - that's assuming it doesn't get too hot up there

 

[Tagged]

That rubber flashing is designed for 110mm pipe - is yours bigger ? Just get a roll of denso and wrap it - that's assuming it doesn't get too hot up there

Yes someone pointed out they person who installed it probably just forced the flashing o and split it.

I've done my own garage roofing but just basics, can you explain what denso is? And have you any ideas on how the water is getting in?

If I look up from the flue I can see slight daylight.

Thanks!

 

[Exedon]

That flue pipe looks like selkirk il or similar.
Lead slate is a mess should always have had a weathering collar instead of that mastic bodge.
What type/make is your boiler?

 

[Harry Bloomfield]

Yes someone pointed out they person who installed it probably just forced the flashing o and split it.

I would suggest the split is due to the continual expansion and contraction of the flue, in relation to the roof. Lead will not be happy with that amount of regular movement.

I've done my own garage roofing but just basics, can you explain what denso is?

It comes in a roll, is very horribly sticky to handle. It's a very loosely woven fabric, covered in an incredibly sticky grease.

 

[Alastairreid]

Best to get the proper lead weathering slate and storm collar.

 

[foxhole]

Im guessing a proper fix is to actually replace it, I'm confused where the water is getting in though

Looks to be big tear in the flashing .

 

[Tagged]

Best to get the proper lead weathering slate and storm collar.

Is this the ones that screwfix sell with the flexible collar and the hard plastic weathering collar or similar to the one that's on it but proper fitting?

Thanks for the help again really appreciate it

 

[Alastairreid]

 

[bernardgreen]

This method of preventing rain water getting through the flue opening may be your answer.

The green cup and yellow "wedge" are fixed and sealed to the roof but not to the flue, the flue is free move up and down through the green cup and yellow wedge as it expands and contracts with heat.

The orange cup is fixed to the flue and sealed to it.

Rain water runs off the edge of the orange cup and drops outside the green cup onto the roof away from the hole.

In reality access to the top of the flue pipe was near impossible so each cup was formed from two half cups glued together.

 

[Tagged]

View attachment 259991 View attachment 259992

Thanks for the links.

I take it my roof pitch is 30 degrees? It's not too steep at all easy to walk on, are these easy to fit myself?

I was hoping to slide the old one off and simply slide this one on and mold it to the roof tiles, fit the weathering collar all seems fairly easy, or is it going to be more complicated than I realise? Will it be tight to get on?

Also I've no idea how to measure the diameter of it. I'll put more of that roof sealant around it until summer time maybe even some of that roof repair paint as the last thing I want is to mess it up in winter and have it gushing in lol.