Cold Air Draft on ground floor

[homefromhell]

hi everyone,

i'm hoping someone could help me as i've got a problem with a house i've bought last year. The house has quite a few problems although i'm interested in solving them one at a time.

Okay, its a standard terraced victorian home built approx 1890. Its got two reception rooms, but its got no basement, so there is about a foot gap between the ground floorboards and some old stones/rubble exists there which i believe is normal. Anyway under the floorboards there is an air brick on both sides of the house which of course circulates air. My problem is that this air is escaping through small gaps of the skirting and is making the rooms and hallway very cold.

I have so far tried the following:-

1. Thick carpet
2. Expanding foam between skirting and floorboards
3. Temporary blockage of air bricks to see if circulation is reduced - still the same (possibly getting air via connected neighbours property?)

Now this is where i need your help and advice. A friend of mine pointed me to a local builder who recommended that i take out a brick under the front face of the chimney in each room, so that all air circulation will more easily escape through the chimney stack. I want to make sure this is safe as i don't want any serious problems with the gas fires or any air circulation.

Below i have drawn to sketches to help you understand:-

1. First one shows how the draft comes out of the skirting as it can't escape.

2. Second one shows the plan to install air bricks under the chimney frontface....WILL THIS WORK?

 

[hotrod]

Firstly, do you understand that when the fires are working they will 'draw' in air for the combustion process from any and all available sources?

 

[homefromhell]

sorry hotrod i don't understand..could you please explain further?

Also i forgot to let you know...the real chimney stack is hidden within this bricked wall, so i don't think i'd affect the gasfires. This bricked wall then simply connects to the ceiling above.

 

[flameport]

A gas fire (or any other kind) requires air to work - burning the fuel consumes the oxygen in the air, converting it to (mainly) carbon dioxide and carbon monoxide. As these combustion products are hot, they will rise up the chimney, and therefore air will be drawn in from elsewhere in the room, typically under doorways, through cracks, under skirting, etc.

This was the primary method of ventilation in old houses, which is why many old houses suffer from damp when chimneys are no longer used.

The only way to stop draughts will be to seal the room - which will then cause the combustion products from the gas fires to spill into the room and kill people. Don't do this.
The chimney flue won't extend below floor level, so inserting an airbrick there won't work. If it did, it wouldn't work properly, as any air entering below the fire could force combustion products into the room, resulting in the same dangerous situation.

If the gas fires are those 'decorative' types which don't need a chimney, then please get rid of them - they are dangerous even if installed properly (the installation of them requires that the room has a certain amount of ventilation anyway, so once again, blocking this will cause danger).

 

[homefromhell]

Thanks very much for your informative reply flameport. Please accept my apologies for asking this as i'm confused, but why would making a hole is an outer wall which only runs upto the room ceiling and which is simply there to make a wonky chimney look straight, make it dangerous?

I'm posting another diagram here, just incase i haven't explained myself:-