Jump to content


  • Posts

  • Joined

  • Last visited

1 Follower

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

George's Achievements

Regular Member

Regular Member (4/5)



  1. It is better to keep the outer leaf up to floor level, this gives the cladding something to meet up with that won't rot and gives the telescopic vent somewhere to sit.
  2. Longer bearing doesn't matter but for a normal sized window (not 4.9m + that is a proper opening), you are safe just adding 300mm. A few mm here or there shouldn't matter. The structural drawing should be highlighting where something is unusual or extra bearing is required.
  3. The foil backing was the vcl. For me it showed the issues trying to retrofit a vcl to an old building. If a building is completely stripped back then it may be possible, but for me, vapour permeable options are more forgiving with no real failure mode.
  4. It was actually an internal wall but was into a boot room/porch which is unheated so effectively like an external wall but without the driving rain. So the source was condensation. Water vapour is everywhere but if it hits a cold surface below the dew point it'll condense. So the foil backed plasterboard (dry lined over gypsum) wasn't allowing water vapour to disperse so the humidity went up and up until the dew point was room temperature (with no CH, room temperature was pretty low). Ripped it off an replastered in lime. I've got some salts crystallising on the surface now but is dry and warmer for it. Assuming the salts are from the gypsum so just vacuum them up and I'll repaint in a few years.
  5. I renovated a Victorian farmhouse! I went with wood fibre - didn't much fancy degassing PIR and there were issues in the house where foil backed plasterboard had been used (literal water dripping off the back of it when removed). I also didn't do a complete gutting of the house so I knew I'd never get a complete VCL, but I did put in MVHR, a ASHP (new CH - well, there wasn't one before) and an extension.. For interstitial condensation, if you have MVHR and you're able to put in a decent VCL then you would think the risk is much reduced.
  6. Agree entirely. (If it was a cantilever (ignoring non-shear forces), if the anchor fails in any way then it is falling out of the sky. But for a floor confined and bolted to walls on either side, it isn't actually going to fall, it's going to locally crack the masonry but the bolts themselves and the resin will be fine, which will hold it in place. So there will be movement, cracking and possibly a loss of restraint on the wall. But it won't look like a catastrophic failure and no-one is going to die. Which is probably why builders happily put a single anchor every 600mm. That plus safety factors plus unlikely to see full live load means they get away with it.)
  7. I partly agree - while you're right, corporations and government need to be at the forefront, there's no reason individuals can't also decarbonise when at these decision moments. Induction is better than gas anyway for almost everything. It can certainly be financially beneficial to move to full electric household if you also get PV, battery storage and an EV. An ASHP fits nicely into that plan. However, if only considering heating systems and nothing else, kWh for kWh, mains gas wins on price. But you'll never be able to make your own gas.
  8. Mains gas is cheaper and will be for the foreseeable future. But in a passive house, the heating value will be so low it's not worth worrying about. Add solar and a desire to minimise fossil fuel usage and ASHP is looks better. However - if it is a choice between a gas boiler but we can afford more insulation OR a ASHP, then choose the gas + insulation. Design the system for low flow temperatures (which you should be doing anyway to get maximum efficiency out the condensing boiler) as this will mean a simple switch to ASHP in the future. For people without access to mains gas, in my opinion ASHP is already the better choice. Oil and LPG is up and up and very volatile and can't be supplemented with solar PV.
  9. Probably a fair few more bolts than that. Your SE will need to look at the load rating for the fixings when put into the wall type you have. I'd happily bolt a ledger plate direct to the wall - but I assume in that photo they had internal wall insulation to run down behind.
  10. Because of the different way in how piles and trench foundations work there would almost certainly be some level of differential settlement. In large commercial buildings the extra expense of a movement joint is worthwhile, but will be a headache in a domestic house. Once foundations get atypical, what should be driving the design is a ground investigation. If the existing design is based on estimates and typical details, it may be worth spending a grand in getting a ground investigation done.
  11. I've only ever seen reinforcement earthed in electrical substations!
  12. +1 for team re-circulation. The grease filters get pretty grotty so it does work as intended (but are easy to wash). I did add carbon filters too but haven't concerned myself with them too much - the MVHR will draw away smells as well as moisture. I also have wood burners left insitu so had an additional reason to not want to create any negative pressure situations.
  13. It might be they've accidentally used B14 & B15 references twice. From what I can see, at GF B14 is a catnic lintel and B15 is a steel beam spanning from C1 to masonry wall. The next B14 and B15 steels are in the ceiling at roof level. They're probably there because the ceiling joists can't span and they wanted the ceiling joists to align through in the same direction as the rafters. I can't quite work out the roof structure but it might have been subcontracted to a roofer. The additional beams may help support there. 3 courses of engineering brick under lintels is a bit OTT but no reason not to in a new build. If the windows are ~2m+ wide then sensible enough.
  • Create New...