Hi
I recently had a new gas boiler installed and the flue terminates below the soffit of my integral garage, which has been converted to a bedroom. To minimise the possibility of ingress of gasses from the plume, I blocked two of the strip vents with pieces of PVC secured with silicone. There were six strip vents on a run of 24 feet, which leaves only four. The PVC soffits were capped on the existing wooden ones. I’ve since been told that these vents are primarily to prevent sweating on the underlying wood. I have sufficient roof vent tiles to protect the roof timbers. Would the remaining four be enough on a run of 24 feet? This would probably mean replacing the fascia and soffit as clearing the blockages would no doubt cause damage. Any advice would be greatly appreciated. Thank you
Are you a tradesperson and able to answer this question?
Capping existing Fascias is never a good idea.
So will have to be removed at some stage anyway. So yes it's best to remove existing Fascias and soffits. Use a overfascia vent which is the best course of action.
Hope this helps. Tristan.
Although a cost effective option, capping over existing roofline is never the best option. Any moisture in the existing timber will be trapped from the clad over and accelerate the rotting process. I would recommend removing all roofline and use an over facia ventilation strip. Your new flue from your boiler should terminate in a position where products of combustion can not enter your property anyway.
You need to let your roof loft breath or this will cause other issues ie damp on the ceiling wood rot etc
Your flume should of been installed a little further to avoid this issue tile vents help the roof to breathe but are installed above the roof felt which will let air out not in
I would suggest new fascia n soffits rather than capping to begin with as this is never a good idea for example if the fascia is wet or rotting and you cap over it then this will lead to more damage later on to the roof trusses or rafters or the capped fascia fixings will loosen over time and just fall off
But saying that blocking off a small section of your soffit vent won’t cause much if any damage
