Multifuel stove pipe too close to wooden plynth?

[woodster]

Hi

I am going to install a multifuel stove into our living room fireplace. I have opened up the fireplace and had the chimney sweeped.

My concern is that I have to fit a 5" vitreous enamel flue pipe from the stove up through a gap of 9" behind a wooden load bearing beam. (It is holding up three rows of breeze blocks used to fill in the gap of the old fireplace). This means that the pipe will only be 3" at best away from the wooden beam. According to the instructions, it should be 14" away.

Is there a way I can insulate the beam against the heat?

Thanks

 

[RigidRaider]

As a multifuel stover user I would strongly advise you to rethink that beam. If you haven't used one before you won't appreciate how damned hot they get! Ours has cracked the plaster all around the fireplace enclosure and the front of the chimney breast. Even insulating the beam won't prevent it from scorching. Even if you don't catch fire, what will happen if you try to sell the house? A surveyor will flag it up.

Could you remove the beam and replace it with a piece of stone or slate in the same size?

If you do have to do work on the chimney breast, take off the plaster for a good few feet away from the aperture. If you can re-plaster the entire front so much the better. This is because no matter how much care you take, the different expansion rates of the plasters will mean cracks will soon appear along the join between old and new plaster. Don't ask how I know!

My advice also would be to employ a proper chimney specialist to set it all up, he will be able to make provision for sweeping with a port in the right place. How good is your flue? The quality of the flue is extremely important with stoves, if you can't achieve a good column of fast rising hot gases very quickly the stove will never draw properly, will be a pig to light and will burn sluggish and get tarred up. The best flue is a SS liner, insulated, but these are £50 a metre. With this the stove will roar like a beast. Next best is a class 1 flue, as long as it's smooth and clean inside with no mortar sticking out of the joints. Also pay attention to the chimney pot and the cowl, you don't want rain coming down.

 

[oilman]

As a multifuel stover user I would strongly advise you to rethink that beam.

Or put some insulation between the pipe and the beam

If you haven't used one before you won't appreciate how damned hot they get!

But insulated flues don't.

Even insulating the beam won't prevent it from scorching.

Now we ARE in the realms of the unreal. I can use leather gloves to pick up metal that would scorch wood.

Even if you don't catch fire, what will happen if you try to sell the house? A surveyor will flag it up.

And on to generating paranoia. This is totally unfounded, and the chances of a surveyor picking anything up is remote.

Could you remove the beam and replace it with a piece of stone or slate in the same size?

Save money and buy insulation.

If you do have to do work on the chimney breast, take off the plaster for a good few feet away from the aperture. If you can re-plaster the entire front so much the better. This is because no matter how much care you take, the different expansion rates of the plasters will mean cracks will soon appear along the join between old and new plaster. Don't ask how I know!

Sound advice.

My advice also would be to employ a proper chimney specialist to set it all up, he will be able to make provision for sweeping with a port in the right place. How good is your flue? The quality of the flue is extremely important with stoves, if you can't achieve a good column of fast rising hot gases very quickly the stove will never draw properly, will be a pig to light and will burn sluggish and get tarred up.

Nonsense!

The best flue is a SS liner, insulated, but these are £50 a metre. With this the stove will roar like a beast. Next best is a class 1 flue, as long as it's smooth and clean inside with no mortar sticking out of the joints. Also pay attention to the chimney pot and the cowl, you don't want rain coming down.

Why should you want the stove to roar like a beast? The manufacturers fit dampers just so you DON'T have them roaring. As for rain coming down, there's one hell of a lot of flues that don't have cowls, not ideal, but not a significant problem.

 

[RigidRaider]

Read his post again, Chief. He writes:

"My concern is that I have to fit a 5" vitreous enamel flue pipe from the stove up through a gap of 9" behind a wooden load bearing beam..... This means that the pipe will only be 3" at best away from the wooden beam."

Are you seriously advising him to stuff a bit of rockwool in the gap or something?

 

[oilman]

3"? Well, there are ceramic fibre boards a lot thinner than that, which I have held in my hand and applied a blowlamp on the other side for 10 minutes. Barely warm. So putting double walled insulated flue, with 1" creamic board and leaving a 1" gap with air flow over the wood should be adequate.

Why you should suggest I would advise using something as ill considered as a bit of rockwool I don't understand. Having said that, rockwool is fine for oil or gas flues.

 

[masona]

This means that the pipe will only be 3" at best away from the wooden beam. According to the instructions, it should be 14" away.

Is there a way I can insulate the beam against the heat?

I have a cast iron fire at the back of my garden in the summerhouse, it's 1.2m of stainless steel twin-wall insulated pipe and at the top I have wooden framework round it with bracket to hold the pipe approximately less than 50mm and goes though the twinwall polycarbonate roofing sheet

At the top of the pipe just though the roofing sheet it's just warm and the wooden frame is not hot at all. I have the roaring fire most night in the winter for the last 2 1/2 yrs and there's no discoloured to the wood surrounding or the roofing sheet. I have no idea of the rules & regulations so I can't comment there.

 

[RigidRaider]

Yes, with double-walled insulated SS flue the recommended gap is 2 inches. I'm sure you could get away with no gap because the outer skin only ever gets warm. But would he want that big fat SS flue sticking down from the chimney? The way I read it, he wants the enamelled stove pipe to disappear up into the chimney, taking it to within 3" of the beam. I don't care how good the various materials are at insulating, I simply wouldn't want wood that close to that kind of heat.

 

[oilman]

................... I don't care how good the various materials are at insulating, .....................

With an approach like that, there would have been a job with John Prescott.