ruggers

I'm just calculating how much timber is required for non load bearing stud walls with 2.4m ceilings and wanted to know, what are the horizontal spacings between the vertical studs. 400 or 600mm? I'm probably going to use 4x2" timbers unless 3x2" is enough. Whats the spacing for any horizontal noggins required, every 600 or every 1200mm? First first floor I have to screw some form of plywood or OSB onto one side of the stud walls for lateral support to the building if this affect the requirement for any noggins.

Oops, I've posted the same post twice. @JohnMo Whats your house heat loss again, I remember it being low? My understanding is, no short cycling is best, a little bit isn't too big of an issue, but lots of it repeating all day is going to be a problem. I've heard heat pumps dont modulate as well as gas boilers but don't understand enough about them to know if they are affected as badly as gas or worse due to them needing to fire up and build pressure? I'm going to need to try to calculate the flow rate and volume of the system for an idea. I can get all of the pipe lengths for 90% accuracy i think and diameters, can size the radiators but not sure how you know the volume they hold.

@Chablais All good feedback thanks. Mine will be 88m2 of UFH ground floor at 100 centres and 55mm screed and upstairs 125m2 8 radiators including the towel rail. Looking to fit 2 mixed units to control a curve for each floor. Heat loss is 6Kw without MVHR, around 4kw with, but need to fine tune this figure & update a few things. 100 fires sounds a lot, how long does the building retain the heat before it needs to fire up once its reached 21C with such a low heat loss? Have you tried lowering the curve, I thought the idea of weather comp was to have it on all the time but with a night set set back 3 degrees less. Do you think the heat loss is too low for the boiler then? I'm not sure if a heat pumps any better in these situations or equally as bad? My knowledge of ASHP's is very basic. What your outdoor design temp in Cumbria?

Just looking at high efficiency low modulation gas boilers vs modern ASHP for a self build with around 4kw heat loss with MVHR installed running weather comp. Two in mind would be a Viessmann 200-W system boiler vs Vaillant Arotherm plus 7Kw. Before ASHP's became popular in the UK, how did we manage/reduce short cycling of gas boilers in low heat loss homes? A Viessmann will modulate down to 1900W. This means that the gas boiler will be at its minimum modulation & starting to short cycle for anything over 9°C outdoors while maintaining a 21°C indoor temperature. How big of an issue is short cycling really? Are ASHP's better at minimising short cycling issues or more suited than gas boilers? Taking away green credentials, ASHP doesn't save anything. Todays prices the heat pump is £125 per year cheaper to run for me, but the annual service is up to 2 to 3x more than a gas boiler. The unit costs more possibly even after a grant.

Thanks. From what I've seen, some have a small later of stone under the pipe, others have the pipe right at the bottom of the trench, but all seem to have the non woven membrane wrapping the pipe and the stone for longevity.

thanks @Temp I'll have a look and save that, I've seen the site before its really good. Option B seems the way to go really.

All of the water drains to a low point ditch but I just want to run a pipe across the high point boundary line so the neighbours water don't run across my land. I can terminate the end of the run into my surface water drain pipe. It's not flowing water, its just wet land in places.

Was the hydrated lime for workability or did it alter the colour?

Thanks Conor, the last thing i want to do in 10 years is dig it back up so thought it was worth seeing what others do. I have a mate who worked in groundwork & says that (A) is fine but I think (B) will be my preference.

I have a site that needs cleared to build on which will require some underground 100mm perforated drainage pipe installed as it sits lower than a neighbouring plot & both have historically been wet woodland. The top soil and sub soil seem to vary between 300-450mm (12 to 18") and then its the clay. Questions: 1. Do I install the drainage pipe onto the top of the clay as this is the lowest point? 2. People have different methods of installing the pipe, which is best? (A) Dig the pipe trench, add a sock over the drainage pipe then surrounding it in stone and then cover with soil. (B) Digging a trench for the pipe, lining it with a geotextile membrane, lying the pipe into it surrounding with stone, and then wrapping the pipe & stone with the rest of the membrane. (A) Seems easiest & some say it works, others say, eventually that the soil works between the stones & clogs the sock sleeve & that (B) is the harder but best option to last a life time. I can't understand how the sock/membrane sheet could clog one way but not the other or is this personal preference?

What ratio was used to achieve this shade and was it just the buff sand cement? I know cement is different shades too depending on the brand. Nice brick whatever it is, really hard to find a decent grey brick and the price of them are expensive. I have a grey brick to use & need a similar tone or mortar or a bit lighter than that, any hints of beige look terrible with grey.

I can imagine that not wanting to see any of it again. How accurate was the amount you used vs what you predicted, did you expect 7.5m3 at 70mm deep?

Another good job ticked off. Be interested to know what the finished level is like once dry and how smooth. Does it still require a self levelling compound over it if karndean or vinyl click was to be used? Did you go with cemfloor or the anhydrite type?

@Canski I was referring to the whole ground floor not just the door thresholds if thats the way it sounded. I was just focussing on heights around LL door openings as thats where the FFL needs to align with. I've just had a look on one site at EPS jablite and it's double the price of PIR while the PIR is competitively priced.

I think I have a good few options now to work to, just interested to know, if i use B&B for the garage floor which will sit 150mm lower than the attached house. What finish do you normally add to the beams and what thickness to avoid cracking as no insulation is required in there.

I'll look into that, 0.11 is fine, no ones policing it. Its actually cheaper to buy 100mm and a 50/60mm than it is to buy a 150mm. Strange. Has to be minimum 150mm air gap below the beams Liquid screed is best reaction times at 50mm, EPS requires 30% more to achieve same U-value as PIR but good shout to make up the height difference if I add another brick making it 300mm.

I think what your referring to where you open up the inner leaf lower down is to allow the slab to bridge the cavity to support the insulation and screed above and prevent cracking. If using B&B, this can be done by either cantilevering the beams out to the inside of the outer skin to support all above, or take a risk & only cantilever the insulation out to support the screed & hope it doesn't crack over time as per attached image taken from someone else's post on here. I really wouldn't care about the inside FFL being 20 or 50mm below the door threshold, all of my doors now have 50-70mm UPVC step overs, it's just because building controls involved with it being a new build. As per my sketch above, I could add 160mm insulation to bridge the gap a little, it's just what to do if i have to add 190mm insulation. I think i jus need to avoid this at all costs is the solution i'm coming to or be prepared to add 220mm of insulation if I want to keep the screed at 60mm. it's a numbers game.😒 Ground clay heave issues so he wants suspended beams & deeper founds where trees were. Just paid extra for this after person who done the plans said heave wouldn't be an issue while not knowing the ground. Don't ask.

@Temp@Canski Thanks for the diagram. With that diagram it's a slab floor so you can easily add more hardcore or concrete to get to your desired finish height. Beam & block seems to work a brick course at a time so you either have to increase insulation or screed. The screed is only supposed to be 50mm. I've allowed 60 in certain areas for any irregularities. I can't lower outside FFL because theres limited fall for drainage so the house would have to go up but outside isn't really a concern. I was aiming for 150mm (2 bricks) step down from inside to outside on my other doors as it's nicer than 3 bricks & as per below sketch, bricks 3,4,5 line up with the 225 block sat on the beams. If I use 190mm insulation then add screed, this puts my inside FFL at well above the DPM door threshold that needs to be level. adding another brick would mean I need 300mm of make up from the beams unless I'm missing something?

I didn't realise it was a whole house calculation. I mean SAP has specified 150mm as 0.10w/m2k, so i could do this and hopefully pass. I only know its incorrect because i was made a few enquiries and some of the insulation suppliers calculated my wall and floor make up for their products and all said i need 180 to 190mm. if i fit 150mm its 0.12w/m2k. Part of my existing house floor has none in, the 10 yr old part has 100mm. Both floors feel as cold as each other. It's easy to get absorbed in figures but having UFH makes sense to insulate better. Was it the inside of the LL threshold that sits 15mm on top of the brickwork? This is what the aluminium ones seem to be on a search. It will be a UPVC door so not sure if it's the same? LABC site says maximum 15mm height difference or you require an internal ramp. I won't know if Im using tiles or karndean until built which will add or remove 15mm by which time it's too late.

With standard beams 150 insulation seems less of a head ache then. increasing insulation to 190 or more and more screed, plus another house course of bricks is £1000's. I'll have a look into them thanks, have heard the names some time ago but thought some insulation must still have to run over the top of beams and block as the beams otherwise the prestressed concrete would have a lot of cold bridging? Going from slab floor to beams requires 10mm more PIR ecotherm told me. I liked the idea of a thinner screed vs thicker for reaction times although with weather compensation it's probably less of an issue.

I have some house plans approved for a masonry build which now need to switch from slab floor construction to beam and block which I've never used before. I'm having trouble understanding how you align the inner and outer leaf brick courses so that the inside finished floor height is level with the cavity wall DPC that the external doors will sit on. If I add a 225mm inner leaf block on top of the beams & then use 150mm floor insulation on top of the beams + 50/60mm screed, it works out well at 210mm, which is under the 225mm block DPC level and leaves some room for tiled floor surface before the low door threshold. This makeup = 0.12W/m2k My SAP has specified 0.10W/m2k using 150mm PIR which you can't achieve, it would require 190mm insulation which throws the heights out a lot. 190mm insulation + 50/60mm of liquid screed = 250mm or 270mm with a tile. This sits higher than a block but 30-50mm too low for a block and a brick to match DPC. How do you make up the floor levels to match low level door threshold/DPC, is it a case of you have to add more insulation and more screed to get to 300mm DPC? With a slab floor you can offset the height of the slab to suit so I could have any thickness of insulation. Is 0.10 vs 0.12 W/m2K a massive difference in a heat loss calculation or noticeable in the real world? I planned on having 150mm two brick courses step down to my outside finished floor level with the exception of the front door which is a ramped access low threshold to comply with regs. From the top down, my floor make up is, Minimum 50mm liquid screed containing wet underfloor heating (May need to be 60mm in some places to account for 10mm curve on beams) 150 or 190mm PIR insulation. 150mm concrete T beams with 100mm block infill and 50mm slip bricks.

I've had a similar price, £650 pump and labour for a day and then around £1400 for 4.5m3. It worked out better to arrange my own cemfloor and a pump guy after shopping around a bit. Not in a position to do this for a year so prices will change slightly, but as of today it's accurate.

Any reason why you chose that one? I'm thinking in some ways, if your well insulated to prevent heat loss and your running it 24/7 with a set back temperature of no more than 2 or 3 degrees, it's all relative especially with weather compensation. I can see a bigger issue with 75-100mm screed and on off timed controls waiting ages for it to heat up from cold and then if it gets too hot you have to live with it for another few hours until the thermal mass is used up.

Is the laitance grinding something thats done shortly after the screed has set, like a week later, or just something that needs done prior to tiling in the future? I received two gyvlon quotes from the same company and one was called Eco FD (Fast drying) and theres no sanding required to help the drying process. Not sure if this means that when FD is used, theres no extra tiling prep required.

I've just been making further enquires on Gyvlon vs Cemfloor prices & to see if one product is better than another at 50mm over UFH & trying to understand the following... Gyvlon has a thermal conductivity of 2.2W/mk Cemfloor thermal conductivity is 2.9W/mk 1. Does this mean that the Cemfloor is quicker to heat up & lose the heat & Gyvlon will be slower to heat up but then retain it for longer? 2. Can you tile onto one better than the other? This might be better placed in the tiling section?