Woodburner advice

foundationsmcr

Hi people, I’m looking for some advice, but some background info first. We’re replacing a gas effect fire with a multi-fuel burner (burning wood and smokeless fuel) in a detached, stone built Victorian house with a large fireplace and chimney breast. It will be a 4.9Kw burner only used to heat the room it’s fitted in and it’s on an end gable wall in a detached house. The chimney stack is at least 11 meters high.

The options I’ve been presented with from various quotes have left me wondering, can anyone give their opinion on the following;

I’ve been told to insulate the liner because condensation will form on the outside and run down potentially causing damage.
I’ve been told to avoid fireboard in the hearth as it becomes unstuck over time.
I’ve been told to choose a metal/fireboard register plate
I’ve been told there’s no real advantage to 904 grade liners as long as you sweep it regularly.

Fireboard or metal register plate and reasons/benefits why
Fireboard or fireproof render on the hearth and reasons/benefits why (we might just leave bare stone)
Chimney flue liner insultation or not and reasons/benefits why
316 or 904 grade liner and reasons why

Can anyone help on these 4 points please?

Thanks

foundationsmcr

Hi people, is there anyone who can help with my queries in any way?

Thanks in advance.

doningtonphil

We have a multi fuel stove and love it.

We chose to line our chimney with stainless steel liner (cant remember grade) and insulation for 2 reasons

1) There is no knowing the integrity of the chimney, especially the mortar. You dont want gases or tar (see point 2)escaping g anywhere except the top of the chimney. Old chimneys were often rendered on the inside. This has likely degraded over time. A couple of smoke pellets prove nothing. To test for leaks a full pressure test needs to be carried out.

2) Open fires lose 80% of their heat up the chimney, so there was always enough heat to ensure the air and gases stayed warm enough to leave the top of the chimney. Stoves only lose 20% or so of their heat which means the chimney might not be as warm as it was 'designed' or needs to be. Because of the amount if volume the air and gases would likely cool and condense before escaping which means that tar and stuff would build up- a potential fire hazard. Also risk of tar seeping through bricks. Shoving a liner up reduces the volume of air that needs to be kept warm and of course the insulation helps keep the air warm until it exits the chimney.

There is no statutory requirement for lining a masonry chimney. Our stoves installation instructions advised us to contact our local council for advice. They (planning/building control) advised I should refer to the manufacturer.

There are restrictions on what chimneys can be used for solid fuel but you sound OK. Make sure you use a HETAS registered installer. Our lining cost about a grand.

Also check for thickness of hearth and how far the hearth extends in front of the stove. We have a metal plate supported on angle brackets screwd to the inside of the chimney. Nice job was done

Camelina

You may get more response if you post this on the Utilities(LPS, heating oil,solid and other fuels board)

alleycat`

foundationsmcr wrote: »

Hi people, I’m looking for some advice, but some background info first. We’re replacing a gas effect fire with a multi-fuel burner (burning wood and smokeless fuel) in a detached, stone built Victorian house with a large fireplace and chimney breast. It will be a 4.9Kw burner only used to heat the room it’s fitted in and it’s on an end gable wall in a detached house. The chimney stack is at least 11 meters high.

The options I’ve been presented with from various quotes have left me wondering, can anyone give their opinion on the following;

I’ve been told to insulate the liner because condensation will form on the outside and run down potentially causing damage.
I’ve been told to avoid fireboard in the hearth as it becomes unstuck over time.
I’ve been told to choose a metal/fireboard register plate
I’ve been told there’s no real advantage to 904 grade liners as long as you sweep it regularly.

Fireboard or metal register plate and reasons/benefits why
Fireboard or fireproof render on the hearth and reasons/benefits why (we might just leave bare stone)
Chimney flue liner insultation or not and reasons/benefits why
316 or 904 grade liner and reasons why

Can anyone help on these 4 points please?

Thanks

Try to help as much as possible.

Insulate the liner, it has the benefit of also making it much easier to sweep (as well as reducing condensation).

The quality of the liner is more important than the grade used. A well made 316 liner is better than a crappy 904 grade liner, but obviously a well made 904 is better still.

I'm told "specflue" make one of the better ones on the market.

The liners tend to rot higher up the chimney as the gases get cold and condense, hence insulation is a benefit.

Can't help with the fireboard question as behind our stove we lined it with "slim bricks".

We have a steel register plate but that is more to do with it coming free with the stove rather than any particular thought on one is better than the other.

As others have said, the Alternative fuels board is the place to get the best answers.

muckybutt

foundationsmcr wrote: »

Hi people, I’m looking for some advice, but some background info first. We’re replacing a gas effect fire with a multi-fuel burner (burning wood and smokeless fuel) in a detached, stone built Victorian house with a large fireplace and chimney breast. It will be a 4.9Kw burner only used to heat the room it’s fitted in and it’s on an end gable wall in a detached house. The chimney stack is at least 11 meters high.

The options I’ve been presented with from various quotes have left me wondering, can anyone give their opinion on the following;

I’ve been told to insulate the liner because condensation will form on the outside and run down potentially causing damage.
If its a good quality liner then it shouldnt get damaged by external condensation at all. Some Hetas fitters do insulate but many now dont, the only real benefit is that the insulation keeps the flue hotter thus giving the flue gases a greater velocity which also helps reduce condensate build up inside the flue.
I’ve been told to avoid fireboard in the hearth as it becomes unstuck over time.
This depends how well it has been secured in the first place, my first stove I fire board lined the inside completely including the register plate. This I installed 6 years ago, year before last I had a new stove installed and it was still attached to the walls and the register plate was still intact.
I’ve been told to choose a metal/fireboard register plate.
Personally now - even though I went with fire board myself I would go down the metal register plate route. Make sure both side are painted with high temp paint before installation to stop any corrosion.
I’ve been told there’s no real advantage to 904 grade liners as long as you sweep it regularly.
You should sweep regularly anyhow ! 904 is a thicker grade thus more robust and less likely to rot. In 8 years of sweeping I have only come across two niknakd liners both were 316.

Fireboard or metal register plate and reasons/benefits why.
Fireboard or fireproof render on the hearth and reasons/benefits why (we might just leave bare stone)
Better off going for slate or tiles imo, stone is porus and will stain with soot - ash etc and you wont get it out. If using stone you should get it in place and sealed well before you install the stove, then reseal it again once stove has been installed.
Chimney flue liner insultation or not and reasons/benefits why
316 or 904 grade liner and reasons why.

Can anyone help on these 4 points please?

Thanks

As above hope that helps you a little.

foundationsmcr

Thanks for all the help people, this is great info. Our installer doesn't usually recommend insulation but I'm planning on staying in the property for many years to come so I'd rather spend a little more now, and get a few more years out of the liner.

I'll post this in the Utilities LPS, heating oil,solid and other fuels board as recommended.

Thanks again all!