plockhart

Thanks all! What way up do I insert the silicone tube? Also does it matter if I hold the gun left handed or right handed? Is there a preferred holy day to do this?

Are some folks advocating doing the full length in expanding foam? Presumably the amps is low enough that I don't worry about cable temperature (1.5mm2)?

Thanks all for the additional replies. Some commentary from me: yes the conduit is on a slight fall the top and bottoms of the battens will have insect mesh but that won't stop the small stuff getting in I suppose

Do you silicone the outside end, the interior end, or go wild and fill the entire conduit 😅 Also do you need to do anything to prevent condensation in the conduit not being able to escape outside? Thanks in advance.

OR maybe I'm thinking about it wrong. Do I seal the inside of the conduit with silicone around the cable as it enters the backbox, and keep the outside end open so any condensation can drain out? if I plug the outside then maybe that results in a build up of water that can't drain out?

I have ran a 20mm conduit from the inside of my garden room to the outside, with the intention of running the 1.5mm T&E to an outdoor light somewhere nearby. I would like to seal the conduit but I'm not sure how to do that as the conduit won't be going into anything for this fixing. The conduit and cable will be between 38mm battens, and will be behind cladding. I have attached a picture of the conduit which I still need to trim back to behind the batten depth. I will most likely have to run the cable to it's destination before putting on the external cladding (since the cable will be inaccessible as I build the cladding bottom up), so that means the seal of the conduit would need to be resistant to movement as I work with the cable at its destination. What would you recommend I do? Thanks!

Thanks for the replies all!

Hi, I am constructing a timber framed garden room and I have not got electrics in it yet. It has insulation in the walls, a warm roof, and an insulated concrete base, and all the glazing is in. The humidity remains consistently high in it (95% humidity vs the 80% humidity outside) and I'm wondering should I try to do anything about it or worry. A few weeks ago it was particularly cold and there was condensation in the corners of the room (tiny sparkles near the top) as well tiny pools of water on the glazing on the inside along the beads. I have 2 trains of thought: - close all the trickle vents, cover the conduit holes I made in the wall (for feeding cables through etc) to try to raise the heat inside to reduce humidity - open all the windows as well as the trickle vents to increase ventilation to lower the difference between outside and inside to reduce condensation What train of thought is correct? I don't know much about how to think about the problem! Longer term I will have a air-to-air heat pump for heating and dehumidifying and will maintain it at a better ambient temperature

Thanks! if will be used for hobbies and maybe some office work in. Likely occupied 8 hours a day most days. I am going to heat/cool it with an air to air heat pump. The windows have trickle vents and then the heat pump can dehumidify

I have made a start - is this what you were thinking?

Ok thanks! Yes it's funny when I was doing all the plans I overlooked this until last night and had a `huh` moment. Just so I understand right, do you propose using insulation tape along all the edges where the joists meet the lower deck, and then taping where the joists meet the wall? Or are you talking about bringing the roof vapour barrier down along the exterior of the building to meet with the insulation at the eaves? If it is that then alas I already have my fascias on with nails.

Hi, I am building a timber framed garden room, which has a warm flat roof. The construction of the roof is: 18mm osb lower deck vapour barrier 100mm PIR 11mm upper deck EPDM I have been working on the interior now, and I am starting to work on the vapour barrier there. Intend to foil tape over the joins of the PIR board in the walls to form a barrier. Then I intend to roll a vapour barrier across the insulated concrete floor, and join it up to the foil on the walls. What do I do as it goes up to the ceiling? It will meet the lower deck of the ceiling, which acts as a break in the vapour barrier. The wall construction from inside to out is: plasterboard 38mm service void 25mm PIR 95mm studs (with PIR inbetween) breathable membrane 38mm battens weatherboard The ceiling finish will just a 12.5mm sheet of acoustic plasterboard attached to the underside of the joists. Attached is a work in progress photo. Are you meant to add a vapour barrier on the underside of the lower deck as well (and thus I would have to go around all the joists)? Or add a vapour barrier to the underside of the joists before attaching the plasterboard (sealing around holes made for electric cables). Or do you do nothing, as it is just an 18mm osb sheet between the vapour barriers and it doesn't matter? Thanks in advance!

I'm just noticing the link to the forum post I was talking about did not go through ok. Here it is here. And attached is the picture I refer to. Thanks for the replies everyone. I continued my research a bit more before I saw these and found a stockist of DriTherm Cavity Slab 32 insulation slab which use case seems similar. I would prefer a flexible product over a rigid board to be able to stuff it into the spaces I have created, but that's just a preference. I will look into the boards as well. My overhang is about 112mm and I already put the fascias on because I was in a race against the Scottish weather putting the roof on, so I just have access from below before I put the soffits on.

Hi, I have been trying to research this topic and came across this post with nearly the same sort of setup I have my PIR continued up the wall as suggested, and I'm wondering what can be used in the overhang between the joists, on the outside of the building. The commenter at the bottom of the thread says `rockwool` but my location means I can't get this easily or quickly delivered. Are there other products that would be suitable? I don't expect any water in here and I am only trying to reduce the risk of condensation. I would imagine `glass wool` wouldn't as it could absorb moisture. Would polyster insulation rolls like this from screwfix be suitable (reading online about polyster seems to suggest it is a bit like mineral wool in the sense it is moisture resistant). Thanks, Peter

Thanks all!