Rain comming down my chimney

[michael]

I have a small unused fireplace in a tiny unused box room in my 19th century property. It comprises of a cast iron fire surround and one of those small open or close flaps that opens up into the chimney. The problem is, when it rains, water must be coming down the chimney as there is always a damp patch on the hearth together with a layer of lime mortar dust.

When I first moved into the property a few years ago, I opened up the above chimney flap for the first time and was able to rake out a good handful of this mortar dust in addition to that which fell out into the fireplace by itself.

The chimney stack itself is about seven foot high merging upwards from one of the side walls on the building and has two chimney pots serving two similar sized fire places which are in staggered positions, one at ground level the other at 1st floor level. It’s only the upper level fire place that has this problem.

I guess there must be a degree of mortar decay on the inside of the chimney however the outside brickwork looks pretty sound and has been repointed with lime where necessary.

At the moment, I'm leaving the fireplace flap open to maintain a good airflow up the chimney and as both fireplaces are unused, I am considering adding some chimney pot covers to stop any more rain coming down. I’m not sure however if there are a variety of designs on the market that would be in keeping with my period property (a former 19th century religious Sunday school)?

Any comments/advice on the above would be appreciated.

 

[Raylea]

Hi,

You do not want it capped off completely if you intend to use it, like wise we had the sam problem, ours went straight up and you could see daylight, so got a roofer round he measured up and now we have a cowl fitted, we don't get rain and we can still use the wood burning stove.

Hope this helps
Raylea

 

[MdB]

If you are going to use the chimney it is important to get the right sort of cap as it will affect the chimneys ability to draw.

 

[Nemesis]

We used to have a cowl, but it tended to get jammed up.

It was supposed to revolve in the wind, instead it didn't, eventually, and smoke was blown down the chimney.

Removal improved things hugely.

 

[michael]

I was thinking of using something like a half round ridge tile but I’m not sure if this is the best and most authentic way of capping off chimney pots, probably not very elegant on a tall and prominent chimney but probably better than metallic cowls. Are there any other types of chimney pot covers that would be more in keeping with the age of the property?

If I go for half round ridge tiles, are they available in a buff colour to match my chimney pots? Can a fire still be lit with this type of cover and do they have to be mounted with the open ends in alignment with the prevailing wind or at right angles to the prevailing wind?

I’ve seen some “hood top chimney pots” on a website http://www.stovesonline.co.uk but I think these are the entire pot and not just a cover.

Should I be bothered about the lime debris in the fire place? Would this deterioration be made better or worse with a fire?

Sorry lots of questions here.

 

[michael]

Sorry
The above website dose have hood top chimney inserts but at £150.50 each I dont think so. Much better a couple of old ridge tiles

 

[cotegreen]

just for your information, when we opened up our chimney we had the same problems with rain coming down, and searched around the internet for a solution and came across chimmey balloon company. The sell inflatable balloons that you put up the chimney, which stops you losing any heat out of the room and stops anything coming down including rain. they are removable when you want to use the fire, then simply infalte again when you are done. we are very pleased with them and they only cost about £25. Have a look on the website. - they do have a slight gap in the corner to allow a small amount of air to flow up and therfore not give you problems with damp etc in the flue/ stack. hope it helps!!

 

[Mark]

If its not in use
http://www.hotline-chimneys.co.uk/products.asp?recnumber=2525

 

[Penners]

If its not in use
http://www.hotline-chimneys.co.uk/products.asp?recnumber=2525

That cap looks as though it seals off the chimney entirely. That's not a good plan. Even if you're not going to be using a chimney you should always ensure that it is well ventilated.

I reckon a half-round tile cowl is probably the most traditional-looking solution to your problem.

 

[MdB]

Item 4 here: http://www.chimneysweeps.co.uk/othercausesofsmokingfireplace.htm

Never be tempted to use one of the cowls shown in the two pictures below.

They are not intended to be use on chimneys that are being use for solid fuel fires. They are ventilator caps, to keep unused chimneys dry, e.g. keep out the rain while allowing some air movement

 

[Flyfisher]

We had a chimney with draw and blowback problems due to lots of trees in close proximity and had an H-pot fitted (google will find pictures). This not only increased the draw but also prevented any rain coming down the chimney.

In the summer we sometimes had 'chimney reversal' that would cause a downdraught, filling the room with a sooty smell. A chimney balloon solved that problem.

Just remember not to light a fire before removing the chimney balloon! (actually, they include a little sign to put in the fireplace to remind you that a balloon is fitted).

 

[MdB]

H pot pic from section 12 of
http://www.chimneysweeps.co.uk/othercausesofsmokingfireplace.htm

 

[Lime]

Before going to the bother of replacing or fitting another pot check the flaunching that holds the pots in place now.
From my experience, most of the water that comes down a chimney is usually the fault of the flaunching, it either being decayed or cracked.

 

[michael]

Thanks for the info Mark
The C-Caps do apparently ventilate the chimney. This is demonsrated better on http://www.chimneycap.co.uk/ - with the link to "How c-caps work"
Do you think they ventilate sufficiently? They certainly seem quite good aesthetically. Not too obtrusive.