Ask the Question

iansas · Joined: 27 Dec 2003 Posts: 40 Location: brook surrey uk

does any one know the correct calculation for fire openings. the hight and width against chimney pot size.
i want to change the old victorian cast iron for a more casual brick opening. i have heard a calculation but don't know what it was.

thescruff · Moderator Joined: 03 May 2003 Posts: 4306 Location: Bath

Dont matter that much or shall I say It a personal choice.

A standard average would be 580 ish high, 550 ish wide and 400 ish deep.

If your going to use the fire as an open coal fire etc and you intend to fit the purpose made fire brick then ask at your local builders merchant what they have in stock.

Mine at home is 900mm H x 900mm W X 600mm D. the one I had in the farmhouse was 100" W x 48" D x 65" to the underside of the oak beam with a 40" cast iron fret in the middle and a 1" steel bar running from side to side to hang the cauldron on, Ahh the good old days.

Flue pots are normally 9".

scruff

iansas · Joined: 27 Dec 2003 Posts: 40 Location: brook surrey uk

what did you put in the couldron Question

thanks again john, my opening is quite high or so i thought 800h x 700w x 600d . i just wanted to make sure it drew the smoke and left some heat Exclamation

i will just put the logs on enjoy(probably need it if my bioler doesn't stop banging Exclamation

)

thescruff · Moderator Joined: 03 May 2003 Posts: 4306 Location: Bath

About 4 gallons of home made soup, you name and it was in there somewhere and we used to top it up every day.

I built the inside up with bricks with a cast iron drain grid built in for the logs to sit on, looks the part and as I get an unlimited supply of wood it cant be beat.

Provided you have an air supply into the room the fire should burn without problems, but don't empty the ash it will burn much better.

scruff

iansas · Joined: 27 Dec 2003 Posts: 40 Location: brook surrey uk

thanks mate.
by the time i get sorted with my heating and fire it will be mid summer. i bet it will be a hot one this year Exclamation

how is your air conditioning Laughing

poolcorgi · Posted: Sat Nov 06, 2004 3:35 pm Post subject:

i think you where reffering to calculated lengh
dont think anybody ever used it Laughing

thescruff · Moderator Joined: 03 May 2003 Posts: 4306 Location: Bath

iansas · Joined: 27 Dec 2003 Posts: 40 Location: brook surrey uk

i finally found out the calculation;

the chimney/flue must be atleast 1/7th the area of the fire opening area.

easy when you know how !!!!!!!! too late, i already put the pot on top and yes its to small..... time to get the ladders out again!
Mad