DCG

Thank you. Very informative and clear for a layman like me! Happy new year

I am effectively intending to do exactly as your neighbours did. I'm in a semi and planning on filling my floor out which will cut the ventilation that exists between my void under my floor and next door's void under their floor. Is this going to be a problem from a BC perspective? I should have mentioned I was in a semi earlier!

My builder is suggesting a vaillant ecotec 637 boiler. I haven't worked out the heat loss of the building but I will be insulating as much as possible during the extension and renovation. My questions are: 1. Are buffer tanks a good idea when there's UFH laid in screed? I ask because I've read that short cycling occurs when the boiler is producing heat that ufh cannot use. But if the ufh heat is going into screed, I suspect it can all be used and therefore there might not be short cycling? Fyi, there will be celotex under the screed 2. If I did have a buffer tank, can I have it in the loft? I was planning on locating my boiler and HW tank in the loft and it makes sense to have the buffer tank there? But I read that given the loft is uninsulated from above, the buffer tank wouldn't work as intended. 3. Any problems with having boiler and HW tank in an uninsulated loft?

Thank you! One final question Is what your neighbours did problematic? I'm planning on doing as you suggest after ripping out the suspended floor. Was also planning on laying a new DPM. What layer would you suggest the DPM needs to be laid at? Thank you and happy new year!

nice eames there

Thanks for this explanation as well btw. It's helped me understand the issue a lot more Now trying to ascertain water table level from neighbours who may have taken their floors up

Garden does flood a bit in heavy rain. But that's about 30m from the house. I've never seen any water collecting near the house. I'd be grateful for recommendations on exactly what to ask my builder to do. I'm willing to take a punt on the water table

I need to order around 9 fixed units. Were the roof maker ones better performing? What made you choose them?

Thanks. That is basically what my builder was suggesting but on another forum some people said that solution might cause rising damp if no air is circulating in the void. I guess your suggestion of DPM addresses that potential problem. Might you have some links where I can read about your suggestion more?

I have come across this solution from continal. But I cannot understand what is going to hold up tons of 8:1 mix? They suggest laying the 8:1 on the celotex or similar insulation that goes between the joists of a suspended floor Anyone used this or seen this used and working well? 09_PUG_Dry_Mix_System_Datasheet_GB-EN.pdf

Thanks Why would you expect performance to be sub optimal in the new bits? I thought UFH was really good for extensions? What would constitute really good insulation for the new and old bits? And what to do with the void? Any insights very gratefully received Thank you

The grey bits are all new. The bit where it says DATUM will be demolished and absorbed into the open living area so will not be suspended floor. The entrance hall, living room and part where dining table and chairs are shown are all on suspended floor. Would be grateful for advice on: 1. Air bricks at the back of the house. Do I need to create a tunnel to the end of the patio (patio extends 5m beyond sliding doors) so that air can enter the void? 2. How to create the insulation for the suspended floor and lay UFH on top. 3. Is is reasonable to wish for uniform heating and cooling of the ground floor given we are marrying two floor types. 4. Optimum number of zones for my ground floor. 5. Should I have hive or similar controlling the upstairs radiators and downstairs towel rails. And UFH controls for the UFH zones? Thank you!

Hi folks I am new here. First post To introduce myself, I have planning for a double storey side extension, full width rear extension and partial first floor rear extension in NW greater London. I am looking for some advice on how to get wet UFH on the ground floor. It's straightforward enough for the new bits of the ground floor but the existing bits of the house are on a suspended floor above a void. I think the void is probably around 300-500mm but probably closer to 300mm. I say this because I have seen some of the void depth at the back of the house when running some new power cables 5y ago. The house is on a flat road so I assume the same depth at the front of the house. My issue is how best to arrange the UFH on the suspended floor. What to do with the void? How to avoid a creating thermal bridge? How to keep air circulating assuming the back of the house will not have any void? Ideally, I would want the whole ground floor to warm up and cool down uniformly. Is this possible if you are marrying a suspended floor to an extension floor? The UFH in the extension will be laid in screed, is this the case for the UFH on the suspended floor too? I want the screed to act as a uniform thermal store and release heat evenly across the ground floor. My friend has UFH laid on a suspended floor. He says his builder filled the void with rubble (!) and then celotex type insulation, then UFH pipes, screed and tiles. His project only finished earlier this year so not really enough time for any issues to present themselves. Is this an acceptable way of doing UFH on a suspended floor? I have heard that filling the void with rubble is a very good way of cutting air circulation and introducing rising damp through thermal bridges. Obviously, I am very keen for the UFH solution not to be heating the void under the floor and instead sending heat upwards. I'd be grateful for anyone who has seen this issue to give some advice on how to correctly go about getting UFH. If it means I have to keep radiators at the front of the house to avoid issues, I'd rather do that than do UFH incorrectly and store up a problem for later down the line. This is a project to create a forever home. I want to get it right first time and happy to spend money on doing it correctly (although there is obviously an upper end to my budget!) thank you folks