Tue, 19 Dec 2023 04:19:38 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303862#Comment_303862 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303862#Comment_303862 Sat, 14 Oct 2023 17:11:00 +0100 Artiglio
A friend has moved into a new home ( to them) and is experiencing issues with mould. It would appear that there is a bit of an issue of cold bridging associated with an rsj used as part of an extension built about 20 years ago ( in as much as the mould pretty much follows the line of the steel )
Use of a dehumidifier has much reduced the problem and they are taking some temperature and humidity readings in the room. Previous owners had ( they say) no problems , however they were a couple that were out most of the day, whereas the new occupants work from home and have 3 dogs.
They are starting to lean towards installing a decentralised mvhr innthe affected room.
Has anyone on here any experience with such units and if so have any recommendations or advice?

Many thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303863#Comment_303863 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303863#Comment_303863 Sat, 14 Oct 2023 17:53:35 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303864#Comment_303864 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303864#Comment_303864 Sun, 15 Oct 2023 10:04:42 +0100 Artiglio They’re friends or friends and i’m not a building professional and i don’t want to get too involved. They need a surveyor and some invasive inspection undertaken to my mind, but not surprisingly it’s not what they want to hear.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303866#Comment_303866 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303866#Comment_303866 Sun, 15 Oct 2023 10:27:44 +0100 WillInAberdeen
A neighbour had this effect where large window openings had been cut into their barn conversion, they needed containers to catch drips during heavy driving rain. Was cured by rendering the outside of the stone wall.


On the dMHRV, we have basic vent axia Tempra in our utility which is effective for drying clothes. Perhaps a bit noisy for a lounge, though quieter than a dehumidifier. There are a new generation of high performance dMHRV coming onto the market, often German, some are very high end with prices to match.


Worth remembering that any MHRV dries the house, only when the outside air is drier than the inside - when it's cool outside (cold air carries less moisture). This last summer and autumn have been warm but humid and difficult for drying. A dehumidifier works all year round.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303867#Comment_303867 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303867#Comment_303867 Sun, 15 Oct 2023 10:53:07 +0100 an02ew http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303868#Comment_303868 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303868#Comment_303868 Sun, 15 Oct 2023 11:23:39 +0100 fostertom Posted By: WillInAberdeenWorth remembering that any MHRV dries the house, only when the outside air is drier than the inside - when it's cool outside (cold air carries less moisture). This last summer and autumn have been warm but humid and difficult for drying.That's right - more ventilation doesn't necessarily cure condensation - at times (esp spring/autumn) can make it worse and then it's a matter of stopping up all entry of moisture-importing outside air. Dealing with condensation by ventilation can be succesfui but requires experience (check out Peter Rickaby) and calculation - just like avoiding interstitial condensation does, in modern high-insulation wall-sandwiches. Easier to cure the cold-bridge at source.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303869#Comment_303869 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303869#Comment_303869 Sun, 15 Oct 2023 13:32:42 +0100 Artiglio
An02ew- the affected room is above (by 5 steps) a lower area that forms a kitchen diner, it looks to me as though the air from the kitchen diner ( which is in use pretty much from morning till evening) is rising up through the house to the sitting room where the problem is occurring.

Way too many possiblities and variables for me to work my way through ( especially as everything is covered up) hence my suggestion they engage a surveyor. I’ll pass on the comment about the dehumdifier versus mhvr . They can make their own mind up about investigating the possibility of any likely cold bridging if and when they get a professional imvolved.

Many thanks all.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303870#Comment_303870 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303870#Comment_303870 Sun, 15 Oct 2023 16:40:04 +0100 revor
https://www.youtube.com/watch?v=ulzcDMJ5Fno]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303871#Comment_303871 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303871#Comment_303871 Sun, 15 Oct 2023 17:09:03 +0100 djh Posted By: WillInAberdeenIf it drains down to where a RSJ has been inserted and there's nowhere else for it to go, then it has to escape somehow, IE into the room.It would likely have shown up as a problem for the previous owners if that were the case, I think. But of course they could be lying.

Artiglio, I'd second your suggestion that they engage a surveyor and accept some limited disruption to find out what's going on.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303872#Comment_303872 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303872#Comment_303872 Sun, 15 Oct 2023 17:14:24 +0100 WillInAberdeen
They seem to be taking over from the ducted kind for some applications, cheaper and easier to retrofit.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303873#Comment_303873 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303873#Comment_303873 Sun, 15 Oct 2023 19:19:14 +0100 fostertom http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303874#Comment_303874 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303874#Comment_303874 Sun, 15 Oct 2023 19:43:40 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303875#Comment_303875 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303875#Comment_303875 Sun, 15 Oct 2023 19:52:20 +0100 an02ew http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303876#Comment_303876 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303876#Comment_303876 Sun, 15 Oct 2023 20:42:22 +0100 Artiglio
The property was originally a small stone cottage that had 2 extensions ( to provide a kitchen diner and a sitting room) , it’s been looked after ( current issues aside) and given the layout and there being no need for a renovation , i would think a centralised whole house system would not be a straightforward installation and i’d almost guarantee that the cost and disruption would make it a complete non starter. To my mind to go for a full system without a decent survey and investigation of the current issue would be foolhardy in the extreme.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303877#Comment_303877 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17992&Focus=303877#Comment_303877 Sun, 15 Oct 2023 20:53:51 +0100 an02ew