New home new problems....

[discobarry]

...Evening all, As you know we recently moved into a lovely 17c cottage which has been causing us a few headaches really the latest being wet. We have had two stoves fitted one of these being upstairs in an existing fireplace so they are newly lined etc but last saturday i went into the bedroom and the stove was full of water in the ash pan and the capping into the chimney was soaked through so at a guess water is coming down the chimney(even though there is a cowl) when the wind is strong enough? it hasn't happened since with the current deluge however the loft hatch which is just above the stove has a big damp patch appeared which is more noticeable as we have just had all of upstairs plastered. I inspected the loft hatch and poked my body through the loft hatch and i couldn't see any obvious signs of damp especially around the hatch surround where i would most expect it, there was a slight damp patch to the left where i suspect it may come from? sorry to burden you all but i need to unload my burdens on to someone else as this new house malarky is stressing me out now and i could do with a little advise and assurance.

Thanks, Aaron.

 

[Lime]

The rain may have been particularly heavy in your area and the house roofing, capping etc. not able to deal with the deluge.
Unfortunately roof repairs are often "ok" until a really heavy downpour occurs or the wrong wind blows the rain where it doesn't normally go.
For example, builders may cut lead valleys too short under tiles or not fit soakers properly.
No one will notice unless very heavy rain occurs.
If you have damp in the ceiling caused by rain, the only way to be sure what is happening is to get up into the loft with a good torch during a cloudburst and completely survey the roof.

 

[worms]

Is the loft hatch insulated? Not uncommon for that to be a cold spot which might suffer from condensation during winter.

 

[agbagb]

This sounds like it could be two or three problems with some links.

It it's entering a newly installed stove with a new liner (twin wall stainless?) and a cowled pot: It could be just a combination of sever wind and rain. If happens in less extreme conditions then something is not quite right, to figure it would need more info about installation.

The wet register plate suggests water is getting inside the stack, so a hole through the mortar or faulty flaunching to the pot. Water on the outside that ends up on the ceiling is likely to be faulty flashing. But the two could be linked if there's holes in the stack.

On the assurance front, it'll stop raining sometime... or to be slightly more helpful, when the problem is pin pointed it should be a relatively easy fix.

 

[discobarry]

Hi everybody and thanks for the replies, the wet patches have almost dried up even though it has continued raining. The roof is being re done in February as whoever did it when the house was renovated did something wrong like didn't tile to the edges properly which could be the damp in the walls of the house although not all of it i suspect. As regards to the stove issue i think it must be something to do with how he as sat the new pot as it was v slightly damp when it was just an open space but got worse that one night since he installed the new cap so i guess i'll keep my eye on that and having fires will obviously help dry it all out.

You just panic when in a new house and things aren't straight forward like your last house.

 

[Sonyaclegg]

Hi Aaron

We are having similar issues with damp patches appearing in very heavy rain. It's all a bit alarming to start with but we have found once the cause is found, it's usually easy to fix. But I agree it can be a tad stressful!

 

[88v8]

Most annoying.
So, water is ducking under the rainhat and coming down the flue liner into the stove. That will rot out the stove in pretty short order given the corrosive conditions that always prevail inside a stove. And, you have water getting into the stack perhaps.
We had both these problems after a new 'professional' stove installation.

Here's the chimney pot that terminates the stack.

Here's how the flue liner was terminated at the bottom of the pot.

I sourced and fitted a 12" rainhat - the installer hadn't wanted to fit one at all because he wasn't that comfortable with thatch and had been looking at The Dorset Model of installation which was written by some prat who has never heard of rain and recommends no cowl at all.

First problem, the 12" rainhat didn't keep wter out of the 9" id pot, so water was getting into the base of the pot and soaking down and dripping on the register plate. Quite a lot of water. Hmmm.

OK, first I didn't really like the way the liner terminated at the base of the pot and then left the flue gas to meander out of the top. This could lead to the gas cooling down and condensing, which eventually would lead to acid attack in the pot/stack. So I bought a length of stainless pipe and sat it on top of the flue liner with an adaptor. Here it is peeping out the top of the pot.

Then I bought a stainless skirt which fits inside the pipe and on top of the pot.

Like this

Then I fitted the rainhat again, and when the new, advert-polluted not improved Photobucket decides to work you'll be able to see it.
OK, here we are. Not very elegant, but no one can see the crude fixings from the ground.

Now, no water can come down the 6" flue liner because it's kept out by the 12" hat, but.... we were still getting a bit of drip down the stack. I decided water must be creeping under the lip of the skirt where it sits on the top of the pot, so I took it off again, and sat it on a fat bead of Soudal high-temp gasket.
http://www.ebay.co.uk/itm/Soudal-310ml-Tube-High-Temperature-Gasket-Seal-Red-285-Degree-C-1-Tube-/180976667853?pt=UK_DIY_Materials_Plumbing_MJ&hash=item2a230ccccd

Now, no leak at all.

All I can say is, get up there on your ladder and have a good critical look. Keeping water out is perhaps low on the list of priorities for some stove installers, but it can be done.

Ivor

 

[DJH]

No wonder you had water getting in! That's a much better job you've done and that should be the end of your problem there. Well done.

 

[discobarry]

An update, we have decided the wall damp must be coming in through the pointing as last night we had one heck of a wet patch appear through one of the stones we have coming through the wall, the stone is soaking and it dribbles down the wall, obviously water is getting in through the outside but we wonder if because the plasterers firstly pva glued the walls first to skim them that it is coming out at such points which highlights the problem further!?!?! and why at this time of year when nobody will come out?!?!?

 

[tobydog]

Possible dumb question alert :roll: .

When I look at various old houses (including our own) all over the country, there are many that have open chimney pots. We have two pots, one open top that serves the wood burner and liner, and one that has a terracotta lid over it that I can only guess vents the actual stack. What happens to all the water that must go down the liner, particularly during the summer we have just had? The bottom of the woodburner has a trap that I think the sweep uses and I can only guess catches all the crap that falls down the flue. Does this also fill with water until it either evapourates naturally or we fire up the burner in the winter?

Whilst we have a huge inglenook in the lounge, the top was taken off it at second floor level at some stage when the second floor was incorporated. There is now a concrete slab at second floor level upon which sits a newer conventional stack. I am hoping the void in this stack is dry what with the pot to it being sheltered from the rain but I can't be sure. There is evidence that there was a flue hole in the concrete slab off to one side in the past but this has been filled in. We don't have a register plate or any other access to the stack.

This is one of those niggling issues that has been bugging me for a while but this thread seemed appropriate to raise it.

Thanks

 

[DJH]

I think I would take a look at your lead flashings discobarry. I suspect wind and rain blowing towards the chimney from the right (looking at your picture) could get under the lead and gain access there. Lead flashings over thatch are notoriously difficult which is why so many cement mortar flaunchings can be seen on thatched roofs along abutments as well as chimneys.

Secret gutters are the solution but these ideally need to be installed firstly before any thatch is laid which is, of course, impossible on a previously thatched property. Another problem with lead flashings on thatch is that there is no way of securing the free edge of the flashings to help prevent wind lifting it although a welt formed along the edge will help stiffen it and, as a last resort, it could be secured to any netting with copper wire although, should that method fail, the resultant damage to the netting could be just as bad as water ingress.

As is common in period properties there are nearly always no dampcourses built into the structure of chimneys (generally speaking that is) as is required today, both just above where the it exits the roof covering at low level and another, just above where it exits the roof.

I suspect as well that your property has been re coated many times as the thatch is above the string/drip course built into the chimney. Any moisture/water soaking the masonry and entering above this course could now dripping into the roof under both the lead flashing and the thatch, which it was intended to do but onto the thatch not under it. Your flashing seems to me to be very mean around your chimney and the bottom right hand looks as though it is sticking up above the thatch and certainly not giving you the cover you need there and is maybe not working as it should.

 

[Greg.Hobson]

In response to tobydog's question regarding where all the water goes in summer . . . .

Our sweep (who has also stripped and re-roofed our mid 1800's stone roof) tells me of other work he has done and in particular of the number of occasions he has visited new installations - with full liners and what-have-you - that connect the chimney (liner) direct to the wood burner with no void above the register plate or anywhere in the chimney. He is adamant that this is dreadful practice and the ruin of many a new stove especially where no flue damper is provided. It is his assertion that the flue from the stove must open after a very short distance into a void above the register plate, from which the chimney proper then exits. I guess the analogy of an "accumulator" (that can gather/release pressure in pressurised systems) may explain what I am trying to convey.

In our own house, which has 2 chimneys with wood burners on the end of each (both "old school" - no liners) the chimneys do not have a vertical alignment. The most direct angles out of the void above the register plate at about 15 degrees for some 20 feet up to an open terracotta pot (which he replaced as part of the roof work). The other traverses the wall horizontally for a good 6 feet before then taking approximately the same angle up to a similar pot.

We have not had any damp problems in the 20 summers we have lived in this house - I guess the off-vertical angle of the stacks spreads any ingress over a large area, thus aiding dispertion. I would not expect problems in winter as the stoves are the main source of heating and therefore any water ingress is soon evaporated.