Wood Burning stoves

[diamondgas]

Cheers Lads I never gave it a second thought to installing myself. Just gave it a wide berth coz I've never done it before!! Now that I've thought about it though there can't be much difference to it. hmmmmmm....! Food for thought! Many thanks

 

[Piper Phillip]

I appreciate it.

 

[blakeecotec]

Wood burner installation is not so simple. Also, you don't have to be HETAS to be competant. NAPIT operate a scheme similar to HETAS as do a few others. Most DIY installs I have seen are poor, many don't reline the the old flue, they don't insulate the flue, many have not done the correct smoke test where you have to close the flue at the top. Many fail the clearances to timber (3 x flue diameter), many use wrong materials, they do not fit the correct ventilation for stoves >5kW and often no CO detector, many get the hearth wrong as well as they do not know the difference between a constructional hearth and an over laid hearth and finally they do not make any flue cleaning access.

I have been to several jobs where the bedrooms are filling with smoke or the smoke comes out of another fireplace when the stove is lit, another had a chimney fire, another where the creosote from buring wet wood had virtually blocked the wire over the flue, causing the owner to get sleepy. etc etc. Wood stoves are as dangerous as gas boilers for CO. Ask the father that killed his son from a bad wood burner install in his shed, or the guy that did his own install and burned down his house, only to find that because he did it himslef he was not insured.

I am not trying to sound over the top, but I see far more dangerous wood burner installations than I do bad gas installs.

Read DOCUMENT J with great care if you are doing it yourself.

 

[diamondgas]

Thanks blakeecotec ... Over the years I've learned to listen to that little voice inside me that says STOP! Hence the question on here. When we went to look around a local showroom I quized the guy on ventilation requirement and he didn't have a clue! Downloading the mi's was a bit clearer but have decided, for safety, to get the external air kit. Would I be right in thinking that these in effect turn the free-standing stove into a balanced flue appliance? Or are the external vent kits used to give a more direct air source rather than the potential issue of draughts?

By the way there isn't any existing chimney, It'll be new up through a bungalow ceiling and subsequent roof! To be honest when we're spending a good few grand on the appliance I want it installed right! The niggle that deters me is not knowing that i can confidently do that

More research needed and any advice would be appreciated... Even if its just to check out the installers workmanship ...

 

[blakeecotec]

The external air kit may work OK, but only if the stove is compatible with it. Air under the grate (primary can be from outside), secondary air over the fire is best from inside the room as it is prewarmed.

Stainless twin wall flue required min 150mm internal diameter and 600 degree temp, 50mm clearance to timber. The ceiling penetration will need to be fire stopped with a special plate that can hold the weight of the flue above the ceiling, then through the roof a roof support bracket is required maintaining 50mm clearance to timber here as well. The minimum flue height is 4.5m, if the roof is tiled then typically the flue has to extend 1m above the surface of the roof, if you are in a windy poistion buy an H terminal or storm cowl. The height above the roof surface can vary depending on the pitch of the roof and the distance from the ridge and other structures. From the stove you can use either twin wall or single skin, some stoves are limited on how much uninsulated pipe you can use. The flue parts must not support the weight of themselves on the stove, so must be bracketed off the wall, either with brackets or a wall plate. If the stoves hearth is deemed less than 100 degrees, then a 12mm overlay hearth can be used, if >100degree hearth then a constructional hearth will be required, details are in Approved Document J. Most stoves with legs have < 100 degree hearths. When reading doc J, it is very confusing and badly written, many people read it incorrectly including installers and manufacturers !!

CO detector is standard fit on these installs. If house is air tight and to latest building spec then 100% of combustion air needs to be provided from outside vent.

Many things to be think about. Twin wall isn't too bad to fit, just bloody expensive, cant be cut, so you have to use adjustable sections which are very expensive. Everyone thinks is is £100/m but you have to add all the brackets and bends and terminal is always seem to come to around £1000 for a average length 5m flue.
If the stove has a fixed flue damper, so if can't be removed easily when you want to sweep it, then you will need a cleaning door on the single skin starter section.

Good luck with the install.

 

[diamondgas]

Many thanks for the info blakeecotec About the only major concern regarding what you've mentioned is obtaining the 4.5m flue height! Is that measured from the top of the stove? We were looking at locating the stove under the beginning of the pitch roof. I'd estimate top of stove to outside would be maybe 2.5m max! I don't fancy 2m of flue with a cowell open to the winds and only a roof slate and a bracket maybe holding it straight may have to rethink positioning the stove closer to underneath the ridge!

 

[AWheating]

its measured from the appliance outlet, min 4.5m no more than 4 bends. Take a look at part j section 2 if memory serves it gives you details.

you should also consult MI as they may allow less than 4.5m.

 

[Nostrum]

Doesn't part J override any manufacturers regulations? Unlike gas you cannot use manufacturers instructions if it is of a lesser standard if I remember?

 

[diamondgas]

its measured from the appliance outlet, min 4.5m no more than 4 bends. Take a look at part j section 2 if memory serves it gives you details.

you should also consult MI as they may allow less than 4.5m.

Cheers Adam Once the missez has decided on the one she wants the next stage of fitting it will come about. I really appreciate your's and everyone else's assistance here ... Come Christmas or the turn of the year we'll be ready for install so plenty time for me to get picking yours and other brains

 

[AWheating]

Doesn't part J override any manufacturers regulations? Unlike gas you cannot use manufacturers instructions if it is of a lesser standard if I remember?

i would think some things like clearances and ventilation quite possibly as they relate to other things other than the appliances design but not for the technical spec/designed working of the appliance, the manufactures instructions should be adhered to imo.