Carrerahill

Underslung insulation is a term I use, and hear used, so I am going to say yes, even if not, I guess the term is technically 100% accurate even if it is not an industry standard term. I also hear face fixed, but I always think of a "face" being vertical. 25*50 would be nice, make sure the battening out is within the warm zone and cannot in itself create a draft zone diminishing the effectiveness of your main boards, you can do this by ensuring the insulation envelope encloses any open areas. If I had the chance to build some my building projects again, the single biggest thing I would increase was my insulation, I just don't think you can get enough, so anything you can do to make it the best, I think is money well spent, we don't heat our extension really, I never installed the radiators, the pipe tails are under the floor if I ever desire, but the insulation is good for 350 days of the year, so that tells me for a small % increase in cost at the time, I could have made it 365 day proof!

Isolate the hot water while on holiday? You could put a 15mm electric valve in, I have that to shutdown my garage supply on the cold feed so I can switch off the water (connection is under the floor so I could not easily add a valve) in the winter.

300mm reinforced concrete slab... for a BBQ? Seriously? First, the slab is too thick, not needed. Secondly, if you build the slab properly, the slab will be a raft found, the BBQ will move with the slab, therefore the tree/BBQ should be OK, as the tree does its thing it may move the slab a bit, but it will move the slab and BBQ construction as one. I think for this I would be happy with a 100mm slab, A252 or A393 mesh set centrally with 50mm cover top and bottom obviously, and 50mm cover at all edges or you risk it rusting and popping and a C20 concrete. You could stick in another 25-50mm if you want, but 300mm is madness.

I would dig out and expose, there may be an F-Connector under that draw pit that you can unscrew (might need a spanner), and pull the cable back to protect, then dig out, add some conduit, proper stuff would be nice but just use some uPVC 20mm conduit or flexi or something, and cover over. I am confused as to why the draw pit is there, is that on your land or what?

I have done both methods, a combination of both and various others. First off, I would highly recommend insulating it now, as you suggest you will do, because it will make your life so much easier and healthier, PIR in a enclosed room is no fun, working with an open roof structure will be good. I would probably work from the outside and fit, as best I can, PIR of 75% depth of the rafters, cut the sheets to max width, then with the help of a handsaw encourage the PIR down between the rafters using the rafter as a guide for the saw, then, a small bead of expanding foam to seal. Once complete, internally fix PIR to the underside and foil tape to create a insulated diaphragm. I would screw them up with long screws and washers and pull them in flush, you only need 4 or 6 if your going to be PBing over, more if left along and less important to get flush fit. If plasterboard needs to be screwed up make sure to mark timber locations or you will have a fight to find them. Depending on how thick the underslung PIR is will impact how I would proceed next, 2 inches (because you have more in between the rafters), I would just fix the PB up through it with 100mm board screws, if you go thicker I would put the PIR in, couple of screws to hold, then add battens fixed up into the rafters or you may have screw pop issues in the future as the PB is sort of floating on a PIR base and the screws are acting more like suspension points - ask how I know. There are of course many other ways too, but this is my methods. It also all depends if that is going to form a boarded ceiling or not and if headroom is important. Mean, you could also put 200mm PIR in underslung, I'd then use lag screws and battens to clamp the boards in.

Could work yes. My OCD is currently getting the better of me though!

The existing one fits so I assume will be OK... I think I will fit a whole kit, I have checked the Velux code and although it is a 2001-2014 model, it will still fit the current EDT (I think) flashing kits. I have had another look today and think I will be OK for the summer, but I will schedule it in for early autumn for a full kit. I might even chase down a sale kit at some point.

Yes, there are, tile up to 14mm, 40mm, 120mm, slate, recessed. (Figures a off the top of my head). Its an easy mornings work, less, but don't know if I am being OTT!

We had the roof replaced, I went up to check it and noticed I could see under the tiles at the Velux, it looks like the original foam weatherstrip has disintegrated and as a result, although the roof has been made up properly, I can no see under the tiles and a strong wind could blow rain onto the membrane, it should all still be watertight but not correct. So I confirmed with Velux that the weatherstrip was indeed the part missing and I need to order two lengths of this foam (tray not included). They come in 2.2m lengths, I need about 2.4m for the sides and 600mm for the top. Total cost delivered will be about £35-40 depending on where I get it, a whole new flashing kit could be picked up today for £80. Might sound mad, but I am thinking of taking out the whole Velux and fitting a brand new flashing kit. Am I mad? Work involved would not be mad, undo the tiles left and right, push the top ones up, undo the top flashing sections and remove, undo the Velux screws, remove the unit, remove the flashing trays, make any tweaks to get the best seal, fit with new flashing kits and reverse of removal. Maybe hour of work, £80 total, and hopefully a fully weathertight brand new flashing kit in a brand new roof. I should have bought a new kit and insisted it was fitted at the time the roof was done, or done it myself when the roof was at membrane and batten stage.

Agree flawed for retrofit - less so for new build and I hope it works as that is how heating is sized!

I won't read the whole thread, out of laziness, but, the way to size heating systems properly is to do heat loss calcs for the building, then size the emitters (usually with 10% margin) then size the source. I have a spreadsheet which you key all the figures into and it spits out the heat loss, you key in your U values for walls, glazing, floor & ceiling, there is a column for infiltration and that's you. We are doing some 3 bed flats at the moment and the heat loss for the whole flat is 4.9kW. Therefore the ideal source would be about 5kW, yet in plenty of flats like this you will find a 20kW boiler (I understand the water generation argument there) but most sources are oversized.

If we were doing it, but a trade will take a day-ish, per phase.

The house I grew up in had had the original woodwork, throughout, painted when my parents and I moved in, my dad wanted it all stripped back and varnished, the old painter chap who undertook the mammoth task of stripping some 20 odd doors, all the balustrades, stair panelling, all the windows, fire places the works, the whole lot used original Nitro Mors and it left the wood in good condition. I must have been about 3 when it all kicked off as I can remember standing watching from a great distance as I was told the stuff would burn me. Looking at the wood work, to this day, it looks great and you would not know it had been once painted. I have however seen doors which were treated differently and damaged is present. So, +1 for the NitroMors - I would, remove all family from house, open all windows/doors, get a good mask with the right rated filter, 3M masks with the Kidney shaped filters are good, you then get the A1/A2 blah blah filter units which click in with a bayonet connection and can be stacked with FFP1/2/3 filters etc. or even other chemical/gas types.

So no sarking boards? Membrane & counter batten and batten whole roof - 1 day Load the roof for tile - 1 day Tile 1 day Ridge and verges 1 easy day. Add another 1 day for gutters and things. Max - 1 week for 1 roofer + labourer, but expect them to be short days. I really think that could be done full in 3 days if you get a roofer who will just crack on and do it. I did a roof 6.4m x 2.7m on my own for most of it (only had help loading tiles onto roof) in a weekend and that included fully OSB sheeting the whole roof. I did the verges, ridge and gutters over a 3 evenings after work. Seriously, if you start tonight you will be done by Sunday.

What is that, 8m long and 2.9m eaves to ridge?

As usual, they are trying to be seen to be doing things and have not consulted with the relative design and engineering bodies who design buildings to actually work it all out first and instead just slap out a new, more onerous figure and think they have done a good job. I am all for improvement in these areas, but improvement must be considered carefully and the impact of other aspects of construction taken into account.

No they are not, far from it. They are a useless non-departmental public body of the Scottish government, there are too many of them, each of them do very little (OK, some may work hard) and are not value for money at all (like most government departments). The only way they will ever be taken seriously is if they are given some realistic power (without going too far clearly) to deal with serious issues. There are reported cases of garages dumping oil in drains and rivers and SEPA have been involved, written a letter to the garages to say, "Bad boy, please don't do that" and yet the issue continues with no meaningful enforcement. I have a farmer friend who knows that raw sewage runs along the bottom of one of his fields, SEPA didn't care. They even know where the outfall is and where it is from. A letter was written I think.

What stage is the roof at? Rafters and sheeting with membrane? Just rafters? Is it 8x2.9 per side or total? If you are at all handy, and the materials are lying there, you could have it finished by Sunday afternoon if you got the sheet on tonight, membrane, counters tomorrow night, batten it on Friday night/Sat morn and have it tiled by Sunday morning ready for verges and ridges on Sunday. Once I have more details on the actual roof make-up I will say how long for sure.

Another thing about SEPA, is that they will rarely enforce anything and actually have very little by the way of powers. They are a bit pointless as an organisation (I worked with them for a couple of years), a lot of civil servants working flexible hours (this was back in the early 00's), not much seemed to happen, the corporate office was quiet on a busy day and really they wouldn't say boo to a baby bird.

This is what I have been looking for! What is that made of, hardwood with MR MDF panels? Who made it for you?

Yes, I know of a large housing development just outside Glasgow where this is the case. Where required, to comply, you must put X m² on the roof, I keep asking why is it done in m² - it should be measured in kW for crying out loud, stupid unit for PV, anyway, so you can go and get the cheapest, lowest efficiency panels and install them and still comply. At work the mechanical engineers will give me the SAP calc results where PV is needed and I based the PV intent drawings on the required m² (rounded up to whole panel obviously), I then take that area and find the most efficient and best peak generation panel I can find at the time then convert it into kW Peak - that is the figure I put on the intent drawing and electrical specification in the tender package, this means the contractor only knows the peak generation figure and will stick to it. I also ensure that the intent drawing (for roof PV arrays) and other associated drawings show inverter positions, isolators and connections to the main switch board to ensure that the design is complete and that it is not just panels I want them to install. The use of a note along the lines of "Contractor to complete design, supply & install fully commissioned operational PV generation system of x kW peak" also helps to ensure that we want a working system and that is what they must tender for. It is usually the big house builders who skip on the inverters and just install the panels as they are doing it all themselves.

But I then fret about the lack of ventilation...

I've seen some blocks omitted every so often to allow final clean out, then a block slid in to close, thinking about it, I think they actually put the block in with a very weak mortar so it could just be easily dug out. The walls were not big (max 4m long) and they got in and pulled out most of the slops. Other options may exist, thinking of my build, I can sort of get into bits of my cavity from the solum through the vent sleeves that go through the inner leaf - if I wanted I could have had more of a honeycomb affair which would have allowed clean out. There will be lots of options from vent-bricks that are left out to other access points. Another option, and one I firmly believes exists, is a skilled brickie who will drop very little down the cavity. Our brickie who has built everything for us, laid our cavity wall blockwork with a bed and mortar mix which just squeezed out and left a slight bump and when it did go a bit further it always seemed to stay put. If the mix is a bit sloppy, you're going to get lots of slop so a good mix is key, and a good brickie who is good at putting down a bed should not really be putting so much mortar down that it is squeezing out enough to fall constantly. On a new straight and level build with good coursing the bed should be pretty consistent and should not be so deep as to be wasteful.

An award for what, 6 brick columns and some lintels over glass? What a wasted oppertunity. If that is what can win you awards then I am going to start using my son's wooden blocks to model some award winning architecture.

No, all BC care about, on this topic, is that you install the correct generation capacity of PV in new builds where the SAP calc needs it to work, otherwise it is just treated as part of the electrical installation and must be installed in line with BS7671. That is it. The batteries really are just not considered. Where BC come into it, is where we need to get structural sign off on existing buildings, etc.