Let's talk Thermal Imaging and Ultrasound

[Tigman]

Sorry how do you know its leaking if there is no smoke in the room ? if the (stack is leaking) I take it you mean outside up on the roof ? a smoke pellet will not make a mess in the room if the chimney is drawing but it will show up outside if there are cracks !

 

[julianf]

As has been said, smoke pellets are the standard check tool for stack integrity. No need to reinvent the wheel.

 

[gaz1]

first test is a smoke bomb

just a reference it could be leaking but not into his property but yours

common practice is to use a liner or rebuild the whole chimney again as once it starts leaking its fun to seal them back up again

 

[waddycall]

Just to clarify - is it leaking gas or water?

 

[tomsutton529]

Just to clarify - is it leaking gas or water?

That is a fine question, and could well turn the tide of this discussion. Its leaking water...

 

[brightspark]

repoint the stack then and check the lead flashing. paint the bricks with Thompson waterseal

 

[tomsutton529]

repoint the stack then and check the lead flashing. paint the bricks with Thompson waterseal

the stack has been re-pointed and the roofers have been out numerous times and say all the work is fine, the stack has also been painted in a seal but not sure which type.

Some more info: the room below the stack is open to the roof and is being used as the living room, whenever it rains the chimney breast has water running down it.

 

[waddycall]

Go up with a hose pipe and run some water on it?

 

[Muppet]

Seen it loads of times , had to take down new stasks and install a lead sheet just befor it entes the roof,
Had a massive problem on a new build, bricks were really hard yet soaked up water like a spoung,
Heavy rain will soak the stone, can be dripping from the glazed pot through the flaunching soaking the brick inside out ,
look at this junction first,
cured this problem a few times on old stone stacks, seal the pot to the flaunching with a polyurethane or polysulfide,
Is there a rain cowl on the pot, .?

 

[DeanH]

Where is the stain? Might be condensation rather than a leak, some salt contamination is able to draw moisture from the atmosphere.

 

[brightspark]

is the chimney used for a gas fire or an open fire or just blanked off below if the latter fit an air brick to aid air circulation

 

[voipio]

Chimney water leaks can be notoriously difficult to cure. Sometimes rebuilding the chimney appears to be the only solution, but even that can fail, as Muppet pointed out. Roofs are laid so that water runs from one layer of the roof structure to another, and then another, plus there's usually roofing felt as backup. The same is not possible with bricks. Whilst the bulk of the rainwater that hits the chimney generally runs down the outside surface, some of it will run down the inside, and will enter through gaps in the chimney materials, or via general porosity, bypassing even the best attempts at sealing the roof to the chimney. Those that have seen the tell-tale run marks from water down the insides of cavity outer walls will testify to this. A good soaking with a water repellent treatment, on both sides of the brickwork, may effect a cure.

 

[tomsutton529]

Go up with a hose pipe and run some water on it?

Done that, that's how we know its defo around the stack.

Where is the stain? Might be condensation rather than a leak, some salt contamination is able to draw moisture from the atmosphere.

The water runs down the chimney breast.

is the chimney used for a gas fire or an open fire or just blanked off below if the latter fit an air brick to aid air circulation

Open fire

 

[tomsutton529]

Seen it loads of times , had to take down new stasks and install a lead sheet just befor it entes the roof,
Had a massive problem on a new build, bricks were really hard yet soaked up water like a spoung,
Heavy rain will soak the stone, can be dripping from the glazed pot through the flaunching soaking the brick inside out ,
look at this junction first,
cured this problem a few times on old stone stacks, seal the pot to the flaunching with a polyurethane or polysulfide,
Is there a rain cowl on the pot, .?

Yes there is a cowl on the pot. As I mentioned earlier he has the stack wrapped in plastic at the moment and I haven't seen him for most the winter to ask how its going. He has however already coated the stack in a sealant but if it was any good is not known.

 

[brightspark]

if its thompsons waterseal silicone chuck a bucket of water over the bricks if it just falls off and doesn't soak in its protected normally it needs 2 good coats to penetrate