saveasteading

Roof tiles are good absorbers of heat, then releasing it overnight, esp as air gets in and around them. In my experience a tiled but uninsulated roof lets in less heat than a modestly insulated ( previous regulations) metal roof. A galvanised or light colored metal roof reflects a large proportion of the sun's heat. I'm sure it's still possible to get reflective flat roof coating, whether white or silvered. I used to use a bitumen paint product with aluminium filings in it. This was to coat inside galvanised gutters. The aluminium rose to the top leaving it as shiny as before. Perhaps this could be applied to a flat roof. I've no idea where to find this now.

Ok. No ufh makes it much easier. But getting a good finish is the issue.

what is the floor construction?

Your logic for this would be of interest. Are you putting insulation onto sub-base or a screed? Reinforced slab? Where does the piping go? My answer: Because it is tricky to get it flat and smooth at a robust stage of the project. Also, most people seem to have overdesigned slabs IMHO. for me, Sub-base, 100 - 150 slab, light or no mesh , pir, pipes, screed. That gives us a good hard working surface, then plumbing and screed in controlled circumstances.

20 really isn't hot. Dress differently, close blinds or curtains. In the Mediterranean, people cope with much higher than that. Commercial buildings in spain are not permitted to use cooling until 27°C. I think we can adjust too. I think I took this pic in a bank.

I've just stuffed rockwool into a plastic bag and up the chimney for the opposite effect, to coincide with the oil and rad central hating being fired up. I've been up at the chimney pot in the past, and the amount of hot air flying up it is shocking. I had one of those chimney umbrellas you may have seen at exhibitions, but lit a fire and it was gone. I should point out that this house is very draughty. But you need control, not just a hole to outside.

Compriband is stunning stuff, and many a reservoir, bridge, big building has it in crucial locations. It has a dimension memory and expands with force to fill a gap, and won't fail in sunlight. I suspect cheaper products, and very much cheaper products, are often substituted in domestic work.

Minuses It costs more / the headroom may be significant / it takes longer to heat up if it has been off. Pluses, it allows for more certainty of thickness on an uneven layer of PIR (which seems pretty much the standard), It will hold and release heat after the supply is off. The heat store principle may allow the exploitation of cheaper power from solar, or overnight rates. But it seems that, in a new house with ashp and ufh most people will turn the system on and leave it on. Me? I'd go for 60mm on an accurate insulated layer. Your average builder may prefer to spend your money on thicker screed to overcome their tolerances.

Can you either explain or point me to a reliable source of information, even a reliable manufacturer's page, of what are silicon, mastic, CT1, etc chemically,/ property-wise and their uses and abuses. I mean in general. I admit to saying silicone as a generic term and I should know more about it. When I replace the blackening and failing shower base seal, fill failed gaps between old weatherboard and aluminium windows and so on, it seems I shouldn't be grabbing any old tube form my stores. Would a good starting point be to only buy big branded stuff and select from their range?

The attached is from 'Building' Magazine this week. It ties in to some recent discussion about power where and when it is needed, and seems knowledgeable and well written to me. So the solution is obvious... no I'll let you read it first.

At least the foundations along with the house. Maybe the drains too as it part of a single, and more efficient, process. It would also reduce the stress and mess of starting again.

Agreed. Their muscles, your attention to detail. Hanging about watching the labour can annoy people, but doing something else nearby can work.

I find I can potter all day. Anything much more physical is doable but writes off the next day. So I make a point of having a few different jobs on the go, heavy mixed with light, and so the posture and muscle use change. I am instructed by experts, that resistance work is crucial to long-term fitness too. They confirm that shovelling, carrying, barrowing all tick that, but I half fill the barrow. In the garden, hedge cutting is the most tiring and causes strain. I used to have a big 'look at what I've achieved' session. Now spread over 2 or 3 days, and there is plenty else to do. I heartily recommend 'no-dig' cultivation. No digging obviously, but it grows vegetables much better too. What's most difficult? standing up from kneeling. I'd like a remedy for that.

= 12.5 half of 5 = 2.5. 35 less 2.5 = 32.5. less 20 = 12.5. = -35 ie 35- 5 =30. Then divide by 2 = 15, then subtract 20. from left to right after first doing the stuff in brackets. If there is officially another protocol or convention in some fields of design then its important we all know. These results are drastically different. Buildings will collapse. It's not personal preference, but crucial.

I don't know this exact material. But the advice above is good, based on rock in different parts of the country. When well graded, like Type 1, it is getting very close to the original density when well laid and compacted. There are now an infinite number of fissure for dampness to go through, up or down, instead of solid rock, but any quantity of water and it will run over the surface and erode it, or puddle. With a single size graded stone there will be gaps at first , and drain nicely, but can erode with foot or vehicle traffic and become of poor permeability...and perhaps dusty or sloshy. Very hard rock doesn't have this problem. So It is quite a big risk unless you can see it in use nearby, preferably with a couple of years use. As above, a geotextile is essential and not a huge cost. Get "non-woven" as it is much better for keeping weeds underneath it. Beneath the membrane the stone can be cheaper, unless for heavy use. BTW I recently got prices for a footpath covering (light use) and it was £45/t for pea gravel, or £120/t for crushed stone. I went mean, and know it will get displaced and mucky, but it was a quick fix.

Ditto. I ended up ripping it all out. That was easy. Then a rebuild. Once the boards are stripped you'll probably find it's worse than it looks, and repairs would be temporary. What has caused it to rot? Don't rebuild the same way.

I cant do sums on this, but my take is this. I studied hydraulics and flow and designed pipelines and channels, a very long time ago. I long ago forgot the maths of it, so this is based on observation and 'feeling'. And I have stood in front of units and observed that the airflow can be considerable. . The outlet is at the front and the chilled air is thrust into open space, and away. Meanwhile it needs to draw in exactly as much air through the back. Your positioning constrains air flow to the back, so it will reduce, the fan will try to work harder, and you don't get the full amount of air through. so it less efficient, and quite a lot I feel. Just increasing from 100mm to 200mm at rear and side should make a big difference...twice as much air flow. It will also be less likely to clog with leaves and webs. If the manufacturer says otherwise, then do what they say.

The ashp could seriously underperform. Its purpose is to be efficient, and you are right to question the arrangement. Is it tucked in this recess for tidiness or due to space constraints? Have you the opportunity to change this?

It's all rather close together, including the heat pump. Will any of the exhaust air be drawn back into the ventilation? Probably, so not ideal, and a bit inefficient. Likewise the ashp is in a recess, so draws in ambient air from a limited area, so is more likely to draw back its own expelled (cold) air, and thus not be totally efficient. Is there a reason it can't be further from the wall?

Aren't these pipes going to be the biggest heat loss of the whole system? I've always overdone it if anything, and would be very inclined to put a boxing around it even after it is properly wrapped. We all put 150mm under a new floor slab, over a big area. Why not £20 more expense at this small improvement / easy gain? Payback one week?

Which suggests that they don't carry the right kit, and tjey work day to day with a bit on the way past from SF, that will fit. So the whole installation is of concern, especially when they lie, or make an excuse or just don't know much, whichever it is. I'd check their insurance too. What is the betting that they reluctantlypripose to fit some economy pipe insulation that will be feeble but also fail in the outdoors.

Preferred by non-technical people and some fitters to escalate the credibility of the fitter who is being sent. Technician is a good term. I'd rather have my meter changed, as last week, by a trained technician than by a Chartered Electrical Engineer. My personal annoyance is a man with a shovel having "Civil Engineer" on his van. However good he is at it. Better him on the shovel than me, as long as he doesn't tell me that a building is designed badly.... they often do. The less knowledge, the more certainty. It's not a protected term like "Architect". But even that seems to be under threat by new terms like 'Technical Architect' with capitals: meaning I think, draughtsman, or architectural technician. Again nothing wrong with the role, but perhaps misleading the public. Architect seems to be appropriated by the software industry too. So I do make a point of a capital E for professionals, and never use the word where it should be technician. Snobby? No. Accurate and informative.

From. so 180 is south, 270 is west . as you say the prevailing wind is SW so 225. That could be a bit sheltered or cause funnelling. But the design guides allow for that, ie not allowing any reduction for real or perceived shelter. No, this is all very sensible. If you keep to standard detailing all will be good. As Gus says, the exposed edges are most vulnerable rather than the whole roof. After gales you will often see loose bits of roof hanging off, but seldom an area of roof. On the steel buildings I worked with mostly. there were standard details for fixings and the eaves corners received twice as many screws as the mid sections.

I hadn't seen this vent theory as being accepted practice. Do you have any backup to it as I'd love to know more? The main thing is never to build a bonfire against a timber-clad house.

Firstly Envirograf. My favourite in this field as they understand fire and the products, many of which they first produced. I haven't contacted them for years but always found their advice interested, realistic and worthwhile. The BCO unfortunately probably will want to see a test certificate for exactly the situation. The purpose of the strip is to stop the spread of flame, and a lump of wood or metal would do it fine. But nobody has tested that as there is no market. A product exists so you probably have to use it. If the manufacturer made the exact same product but wrapped in red , and tested with timber, or wrapped in blue and tested in metal cladding, then those would be the test certificate that existed, and you have to use the red or the blue. How about intumescent paint on a timber block or metal profile? A pragmatic and knowledgeable BCO might agree to it: after all it has the magic word intumescent. I'm not guessing btw. I've worked on this a lot, including a high level course, but there were no qualifications awarded. Yes, but the effect of heat rising is still there. A fire spreads very rapidly upwards, chimney effect or not, as the material above is preheated, and then a flash flame can occur.