Hi, I am installing an inward opening new front door where the opening is the same width as the hallway. So the existing plasterwork is around 14mm. The architect has specified 37.5mm insulated plasterboard. So if this is fitted then it will stop the door from opening. I am currently looking at Velfac (25mm between edge of frame and door) and 21 degrees ( 40mm on hinge side).
Any thoughts on other options to prevent cold bridging here?
Thank you
Jo
I am having a problem visualising your hall. Does it have any external walls? If it is the same width as the door that seems unlikely. The root question is “why insulate the hallway walls, other than above the door?”
The internal blockwork is in line with the brickwork outlining the external door opening ie the hall is the same width as the doorway (less the thickness of the plaster). This means that if the door frame was eg 25mm all the way round then only about 12mm of that would be exposed internally but with eg 10mm tolerance on each side then about 20 mm of the door frame would be exposed. The internal insulation is designed to reduce any cold bridging at the edge of the door-- in the same way it would perform that function with window reveals.
Does that make more sense?
thank you
Jo
Excellent explanation. Thanks.
To fit the requisite amount of insulation without unduly narrowing your hall, allowing the door to open and fully insulate the frame and the join between frame and wall you might need to remove the original plaster, parge the blockwork and then fit the insulated panels. Of course that will involve a lot of additional expense, mess and disruption compared with stripping the wall covering and fixing a thinner insulation board.
If we assume that either way the internal dimensions of the wall shrink by 75 mm then either you need to get a door frame that deep or fix a narrower and smaller frame to something like Compac foam to insulate between wall and frame, and then fit an external trim for tidiness and to protect the foam from UV light. (I contacted Compac foam a while ago to enquire about temporarily exposed foam between stages of my project and was told that it starts degrading in UV.)
I would specify thicker insulation above the door and over the top of the frame. That should be at least as thick as the rest of the outside walls.
Is your front door flush with the front of the house or set back?
Mine is set back, with the resultant porch wall being shared with the lounge. According to my infrared thermometer, on an unexceptional winter’s day the temperature at the porch end of the living room wall is 2°C less than a few centimetres away from it. Either I need to insulate that area of wall, preferably in the porch, or I should move the front door to be in line with the rest of the thermal envelope. I intend to do the latter. To keep Mrs. G. happy I will be postponing that until we are ready to decorate the hall. For some reason she doesn’t want a messy junction on show. 
Not sure there will be space for this as the frame will go to the lintel unless I specify a shorter door. I guess building control have a minimum height for an entrance door so will need to look that up.
The front door is set back from the front wall in the same way as the windows are so I don’t think it is the same situation that you have. As far as the wall goes It does look as if the wall ties are further spaced than recommended though-- a meter apart horizontally and maybe vertically too
Do you mean the depth front to back so the edge of the insulation is flush with the front wall edge and goes to the edge of the block work or do you mean height wise - top to bottom ?
Ah, I see the ambiguity now. I meant from the door frame to the ceiling above the door.
Your description of the hall and the plans for it don’t mention the area of wall above the door but unless the door is exceptionally tall there will be an area there that needs insulating from ceiling (or preferably the floor boards of the room above•) down to overlapping the door frame.
• better still, continuous insulation from loft insulation to DPC.
Interesting point, I am assuming there is a lintel directly above the door as the depth of the wall above is consistent with the depth of brick + cavity + blockwork.
There will be a lintel. Probably not an insulated one, so as you say, the IWI needs to cover it. Occasionally bungalows are built without door lintels, relying instead on the roof plate.
This needn’t be an issue, so long as there is minimal movement in or of your property. I take it that you do not have cavity insulation, otherwise you wouldn’t see the ties.
Are you planning to insulate the cavity later? If so it would be wise not to choose any insulation that expands in situ as that will put pressure between the leaves of the wall.
Oh bother, I have exposed Compacfoam around my newly fitted windows – an insulating sub-frame between the windows and surrounding wall. I will be cladding it with wood later, when I get chance (I was thinking strips of Thermowood, painted with Osmo oil to the exact RAL colour of the windows, for a perfect match).
How long have I got?! Sounds like I could do with covering it up for UV protection over the summer until I can clad it properly. So handy you mentioned that, ta!
If I remember correctly, Compacfoam starts to deteriorate after 3 months’ exposure to UV but that will presumably depend on the level of UV.
I have a little project coming up where I’m just thinking of painting the foam, although when I insulate the rest of the area there will not be continuous insulation, the thickness of a couple of dry coats of paint probably won’t make much difference. If anyone with PHPP can verify or deny that I’ll be happy to listen.
You can get custom frames from 21 degrees, meaning another 33mm possible which gives more to insulate up against. The hinged side is usually the worse case side, so whatever frame you choose (e.g. GBS78 or 98) you’d then find out what that is, add maybe another 33mm and see. But then the other consideration is door opening - had a case recently of the existing brick opening being fairly narrow, then if you add a chunky framed door, the actual clear opening width was quite narrow (I’ve got the info from 21 Deg I could upload, but can’t see how to do it here). We got around it with a plan to cut back the inner leaf and recess the door frame into it (less frame visible from outside), and also the same on the threshold but with Compacfoam in place. I guess if all that not possible, or if door is already procured, you could consider Thermablok aerogel for the reveals.
There is blown fibreglass type but wall has been removed to fit a window-- hence the discovery
Good idea, ---- however------I have had a quote from 21 degrees but sadly they won’t just do a door order- or they will but charge full delivery cost of £1000 on top and also say they can’t take delivery to Golcar as part of another pallet as we could pick it up from there.
Building control specifiy that all the beading needs to be internal for first floor windows and their alu clad version of the 78 has external beading.
Been talking about the use of compacfoam with the builder in relation to fitting of the door and he suggested that you would stop the compacfoam short of the outside edge and fit a strip of compriband expanding tape to be front facing.
I can tell that you have a builder who understands the issues of low energy construction and retrofit. I’m envious.