Aren't chimneys supposed to be hollow?

[Steve]

Hi

Any ideas on the following problem gratefully received.

We moved into a bungalow a few months ago. The chimney in the kitchen appears to have been bricked up and it looks like (from old pipe work) that it was once used to vent an oil-fired boiler.

The chimney is not capped, and there's evidence of damp on the chimneybreast upstairs, so I thought I'd put in a vent near the bottom. The plan was to drill a few large holes near the base of the chimney in the kitchen and cover them with a grill.

I've drilled in from the front and side but the chimney doesn't seem to be hollow! The chimneybreast is 19"wide. I've drilled to a depth of 10" from middle of one side and still haven't broken through. If the chimney is symmetrical, this suggests it isn't hollow!

So, any ideas on how to proceed, gratefully received.

Festive greeting to all.

Cheers,

Steve

[Andrew Mawson]

kitchen

chimneybreast

chimney is

The actual flue will probably only be 9" square, so a small proportion of the width of the chimney breast. It is also quite common for the flue not to be straight but angled, particularly if the same stack is used on more than one floor.

AWEM

[Ophelia]

Oh dear How will Santa get down:((

[Weatherlawyer]

It could be 9" clay pipes with a stainless steel insert if there was gas or oil used in it. You have got the right room have you? How about some piccies to facilitate the detective work? (Inside and out please.)

The top needs a cap. Perhaps a paving tile; which should be raised slightly for venting gaps in the mortar. But before doing that check for jackdaw's nests. Drop marbles or somesuch down it to guesstimate and have someone inside listening for the likely backing.

Could be muffled with debris though, especially if the front has been bricked up. You should check the leadwork while you are up there and look for loose and/or broken tiles.

As for the inside, presumably you are going to strip the wallpaper over it? Wet the plaster and it will tell you where the brick joints are (hopefully.) The straight joints are the infil.

[Autolycus]

Are you sure about this idea? The kitchen often contains quantities of warm, moist air. Let it into the chimney through your vents, and it will hit a much cooler surface in the bedroom. Result - condensation - damp patches.

Hang on... bungalow ... upstairs??

Can you vent to the outside instead?

[Steve]

Many thanks for the replies, all.

I'm rethinking in the light of Kevin's comments - that ventilation would let loads of damp air from the kitchen rise and condense on the higher part of the chimney. Maybe that's why there was no vent fitted.

(Incidentally it's a 'dormer' bungalow, so there is an upstairs!)

If I go ahead, I'll try a few more deep holes.

Merry Xmas and Happy New Year.

Steve

[dg]

Moist air from the kitchen would not condense as to be a problem - after all it will be getting through ventilation and so moisture will be evapourated and expelled via the top outlet. Its more likely that no vent was fitted because the previous owner/builder was not bothered or did not have a clue about the need for venting the flue

The fire recess may be filled up so a vent at higher level where the flue would start may be possible - centre of the brest and about

900-1200mm up from the heath to miss any lintel.

Alternatively put a vent in the brest in the upstairs room below where the damp is

Wait at least untill boxing day to do any drilling though! lol

dg

[Steve]

Thanks for that dg. Yes, a vent upstairs sound like a good compromise.

Cheers

Steve

[Christian McArdle]

Chimneys are rarely symmetrical. Usually the downstairs flue is on one side and the upstairs is on the other. Normally the flues appear central at the opening (for aesthetic reaons) and then immediately rise diagonally to one side so that the opening on the next storey can also appear central.

Christian.