How to repair chimney roof leak?

[loserkite]

Hi everyone,

Sorry but total novice here. There is a signifcant gap in my chimney, which I believe is the source of leak of rain into my house

I went up the roof and saw that this gap (see attached photos). Judging from the white residual, it looks like there has been some previous work done, but it has been removed or falled off for some reason.

Looking for advice on how to repair this.

Thanks

[JacobZ]

Hi @loserkite,

A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us,

Typically, for roof penetrations on metal roofs, you would use a Dektite flashing in a suitable size to fit over the flue.

Check out the installation guide here - Dektite.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[loserkite]

Thanks Jacob. I have bought a dektite and done the round part of the chimney

If there is a leak around the bottom rectangular base. Are there any products like dekittie for the bottom rectangular base? 

That is quite large in size. 

Thanks

[JacobZ]

Hi @loserkite,

You could seal up the bottom of the rectangular flashing with Weatherproof Byute Flashing Tape.

Just make sure you give the metal a good clean with some isopropyl alcohol to remove any contaminants that would affect adhesion before applying the tape.

It is unlikely you'd need it, but if need be, you can also add some Selleys 310g Translucent Roof And Gutter Silicone Sealant to the top and bottom edge of the tape.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[loserkite]

Thanks Jacob.

Also, the rain seems to pool on top of the rectangular base instead of sliding down a slope

It is very flat with no real gradient. In fact, there may be even a tiny divit in the base leading to pooling

Any suggestions how to fix that so that the rain moves down the rectangular base rather than have rain accumulate on it.

I have attached a picture before I installed the dektite for the round base

Thanks Water pooling in the rectangular base

[JacobZ]

Hi @loserkite,

I think it is best to just manage the potential entry points for water and allow the water to sit and dry naturally.

Unfortunately, the only way I could see to fix that issue is to remove the metal, create the fall on the surface beneath and then reinstall it. This would obviously be quite an undertaking.

If the water pooling is not causing any issues, I don't see the benefit outweighing the cost to have this done.

Let me know what you think.

Jacob

[loserkite]

Thanks Jacob; appreciate the advice.

Are there any plastic products that could potentially create a small incline that will allow the water to flow down?

[JacobZ]

Hi @loserkite,

Unfortunately, no, at least not that I am aware of.

Perhaps @Dave-1 or @Noyade may have seen something that could work?

It might be a silly question, but is there any way to access the underside of the metal flashing? 

If there was, you might be able to install something to prop up the dip that little bit. 

Let me know what you think.

Jacob

[loserkite]

Thanks again Jacob

I can see stain marks inside the house from  rain leakage which appears that have been there fo rmany years. Hence the extra precaustions that I am taking.

I can not access the underside of the metal flashing. It all appears well sealed

[Dave-1]

Good Evening @loserkite 

It looks like the metal cowl that should have gone over the top of the chimeny and then glued down to the square riser has gone walkabout... The white stuff looks like something that would have helped secure it in place. Maybe when the last person cleaned the chimmeny or replaced the outer tube they forgot to put it back.

Just went to see if i could find a purpose made flashing, looks like the one that @JacobZ has mentioned (same style different brands about) is pretty much what everyone uses. I would be using that one to seal the chimeny tight so water wont travel down the outside tube and into the roof space.

With the water pooling, Like @JacobZ has mentioned id be tempted to make sure you seal the chimeny with the flashing and the base of the square unit and then just let it dry naturally. Trying to get a bit of a rise so the water would drain will be a hard effort for sure and I dont think you will get much of a return on it.

Dave