28-08-2012, 09:41 PM
Hello Mark, you are in my view correct about not filling cavity walls, the cavity is there for a reason as you say, if the wall is not exposed to the elements for whatever reason then it is possible to do it with no real ill effects but that scenario does not happen very often, to seal everything up is madness but that is what people tend to do, they build houses the wrong way round it's all vested interest driven I'm afraid, in my view the cavity should be a lot wider in todays construction thus allowing a greater thickness of slab insulation to be fitted whilst still maintaining a satisfactory air flow, we have the technology to build decent energy efficient housing but for whatever reason it's not used.
You can beef up your loft insulation by the way but you will need to ensure that the roof is ventilated for it's whole length where it makes contact with the wall plates ie: between the rafters, there are various plastic vent systems available or you can make your own up using thin plywood and timber batten, the vent should vent to a vented soffit if possible, if you upgrade then as you say Kingspan or Celotex is good stuf with some rockwool on top, all my wooden floors are insulated with kingspan laid in between joists on batten ledgers.
I have spent a lifetime doing up old properties both for ourselves and other people, we have lived in roses round the door cottages and converted stone barns etc, trouble is you have to heat up 200 tons of rock before you can heat yourself up, what's that all about. We were fortunate enough to aquire the place we are in now which is mainly timber based, it easy to keep it warm whilst maintaining enough ventilation, all the windows I put in are fitted with trickle vents and we spent several thousand pounds on insulation alone (Kingspan & Rockwool) but it has been well worth it, the place keeps bone dry.
If anyone has down stairs walls that are solid and not cavity then you can convert them to cavity either by using timber frame (you have to know what you are doing) or lightwieght block such as Thermalite/ Durabloc etc, we did this at the last property we had which was a barn conversion, two of the downstairs outer stone walls were below ground level (barn built into side of hill) I allowed a cavity space (air) and built the Thermalite wall straight off the concrete floor (with DPC) every other course was tied to the stone wall with SS screw in wall ties, the cavity was vented to outside at the front and one side of ythe house (the walls that weren't below ground level, the result was absolutely no damp whatsover, not even after 20 years. You can cut Thermalite, Durabloc etc with an old gash handsaw.
Below is some of my handy work from a barn we converted.
Lawrence.
You can beef up your loft insulation by the way but you will need to ensure that the roof is ventilated for it's whole length where it makes contact with the wall plates ie: between the rafters, there are various plastic vent systems available or you can make your own up using thin plywood and timber batten, the vent should vent to a vented soffit if possible, if you upgrade then as you say Kingspan or Celotex is good stuf with some rockwool on top, all my wooden floors are insulated with kingspan laid in between joists on batten ledgers.
I have spent a lifetime doing up old properties both for ourselves and other people, we have lived in roses round the door cottages and converted stone barns etc, trouble is you have to heat up 200 tons of rock before you can heat yourself up, what's that all about. We were fortunate enough to aquire the place we are in now which is mainly timber based, it easy to keep it warm whilst maintaining enough ventilation, all the windows I put in are fitted with trickle vents and we spent several thousand pounds on insulation alone (Kingspan & Rockwool) but it has been well worth it, the place keeps bone dry.
If anyone has down stairs walls that are solid and not cavity then you can convert them to cavity either by using timber frame (you have to know what you are doing) or lightwieght block such as Thermalite/ Durabloc etc, we did this at the last property we had which was a barn conversion, two of the downstairs outer stone walls were below ground level (barn built into side of hill) I allowed a cavity space (air) and built the Thermalite wall straight off the concrete floor (with DPC) every other course was tied to the stone wall with SS screw in wall ties, the cavity was vented to outside at the front and one side of ythe house (the walls that weren't below ground level, the result was absolutely no damp whatsover, not even after 20 years. You can cut Thermalite, Durabloc etc with an old gash handsaw.
Below is some of my handy work from a barn we converted.
Lawrence.
