Moggaman

What are the key checks to do before your blown bead contractor leaves site to ensure that the cavity is fully filled?

Would 200mm blown beads bring you under the 0.15 passive level?

What u value was that please ?(assuming u did PIR at 0.021)

Yes but I want to put all my insulation in the cavity and do a sand cement /skim render finish on the inside. The sand cement is my airtight layer..seems to me the service void is added cost. Where is the airtight layer in your design , a large coat.. couldn’t i parge coat the chases?

Thanks.I’m talking about behind the electrical boxes where it wouldn’t be plastered ? I presume the space for the box and cable are chased out... the cable part can be plastered over grand but behind the box can’t.just thinking in terms of airtightness

Hi all i wonder why people on new builds put insulated plasterboard on the inside of the external wall. I presume its because they do not want a wider cavity.... but if you want a certain u value shouldnt u widen the cavity to allow all the insulation to be put in there... also means you can plaster the inside wall to provide your simple finish,, am i missing something? As an aside, if in a masonry build you put all your insulation in the cavity and you plaster and skim the internal wall, how do you make electrical sockets (for instance) airtight? Also i note many masonry houses near me have 350mm cavity wall with 110mm xtratherm insulation inside... I presume a full fill cavity with PIR board is a good option Thanks

Joe90, there are special wall ties for cavities over 150mm.... are they expensive compared to normal ones.... also the thermal conductivity of the batts is probably around 0.037 as compared to 0.021 for PIR so I am just wondering was it ease of construction you did it this way because Im sure a thinner layer of PIR would have achieved the same u value. Just interested to know your thoughts Thanks

I’m in the west of Ireland too and aim to build towards passive too.. I think the expertise in terms of PHPP is probably greater and most prevalent in the UK. can I ask though, what stops me from hiring a Uk Consultant to look at my drawings and running it through PHPP. ?. I won’t be looking to get it certified , I just want to know where my design stands ?

Hi. I have a flat roof connected to the main house. The walls are icy with thin render - the final coat being a 2mm acrylic render. There is drop of water coming into the room below when raining for a while. I have come to the conclusion that the water is entering through the render and down the back of the lead which eventually means drops into the wardrobe . I want to paint on a sealer to the external surface to test this theory . The sealer would need to be transparent and I would need be able to paint over it as we want to repaint the house next year. can I ask you to suggest some products please. I live in the west of Ireland(Not coastal) , rain is something that is common on a daily basis. Thanks

Hi.Is there any thermal bridging issues with an overhanging roof . Mine will stick out about a metre from The front wall. I think not but just checking

Hi. wondering if a 30 degree pitched A roof with slates is ok ... obviously a 40 degree roof would be better but I have a definite ridge height that I have to work to. I know structurally it is fine ... I am wondering more so about wind driven rain? thanks Moggaman

Hi. I can’t find much on the forum about this but in winter time if you have houses burning fuel for fires around you , how does the smoke from their chimneys affect the MVHR ... will it bring in warm, ‘fresh’...chimney air. I know there is a filter but I’m wondering have people experience of this Thanks

i dont trust external wall plaster on insulation long term. i trust sand/cement render. Could you explain your comment a bit more for me please... risk of condensation if.......i run pir inside the internal leaf or if i have pir in the cavity alone?

We have a wood burner. A lot of smoke would come into the room when refilling. We installed a H cowl on the flue as it sits under the ridge line. It improved but it’s bad again . Would the orientation of the h cowl matter ?. I was told the h cowl solved every down draft problem . It happens in all weathers . thanks

U value of 0.15 perhaps. What u value did u achieve and can I ask did u fix 25 pir to inside of inner leaf.... isn’t that just the same as insulated plasterboard... people are suggesting they dew point may be an issue with this design?

I did some U Value Calcs and its seems that the PIR Board Insulation like CavityTherm or Xthratherm is the best option (In theory). With a thermal conductivity of 0.033 ish for bead, u would need to go to 200mm wide to make up the difference. What worries me though is that I read an article this evening saying that if the boards are not flush with the inner leaf, that the effectiveness of the insulation is reduced MASSIVELY.... I think a 5mm gaps is allowed. I am not in the house building area but I was wondering for those of u out there that watch insulation boards get installed regularly...is it possible to get them done near perfectly?. The issue i believe if they are not is that thermal loops will occur and suck the heat from inside out... Also on a slightly different note, I saw a post by someone condemning insulated plasterboard on the inside face of the external wall. I thought there was only positive with that stuff but maybe there isnt...hanging stuff for example...will chasing for wires reduce the effectiveness.. Lots of questions ... Thanks

Thanks everyone.... toothpicks did the job and it is fairly stiff....?

Hi. Locker knob has come off. It just twists endlessly on the screw sticking out. Any of ye knowledgeable folks know an easy fix pls. Thanks

I just googled seized pumps and saw that if u take off the bleed screw and stick in a screwdriver and manually turn the pump it may unseize it...( when the heating is off)...yes the boiler is firing and we have had no problem with showers.. only turned heating in today after 4 months... pump beside boiler was hot

There is a circulation pump in the garage that is hot ... see second picture. If I undo the screw in that pump and move the propeller with a screw , will a lot of water come out? thanks

Hi. I turned on central heating . Boiler is on, pressure is in system but rads not turning on. See pic ..pump light on...making a lot of noise.... any advice thanks

Hi My house design has 2 large roof windows in a 38 degree pitched roof in each bedroom. Bedrooms are 4m x 3.6m. The room are facing south south east. Prevailing weather is from the South South West. I have never or any of my family for that matter slept for any length of time in a room with with roof windows. We get quite an amount of rain where I live. My fear is that the noise will be more than we can bear. Rather than change my design to dormers.. what are my options to reduce the potential noise.. i have read about 1. triple glazing .... is that really effective..anyone got experience of this working 2. external electric shutter on the roof windows.. again has anyone experience of this and is it the obvious suppliers I should look at. Thanks M

I am trying to keep the first floor to 300mm thick in total max... ridge height is set. Can’t go any higher .

My design has all 3 bedrooms upstairs under roof lights... how do I design against fast decrement delay ... choose my materials wisely?