Jeremy Harris

That may have been an arrangement to deal with heavy rain, perhaps. One problem with gravity sand filters is that they don't like high flow rates or turbulence, so perhaps the weir arrangement was there to calm the flow to the second stage? I'm sure that the combination of a relatively small surge tank plus a modestly sized gravity sand filter, feeding a large underground storage tank would work very well indeed. Using something like Turbidex (http://gapswater.co.uk/acatalog/Turbidex--1-cuft-5955.html#SID=251 ) instead of sand would give significantly better filtration from a filter, and be easier to backwash clean. I wonder why this sort of arrangement isn't used more often? None of the commercial rain water harvesting systems I've seen seem to use something as simple and effective as this.

Our roof has 50 x 25 counter battens at 400 centres, then 50 x 25 battens at the slate pitch (off the top of my head around 170mm IIRC). The GSE trays fit directly to the slate battens, and in my case the spacing was such that we didn't need additional battens where the trays were fitted. We had the frame company fit the counter battens, membrane and battens, on the pitch I specified (including the shorter pitch for the starters at the eaves, to get the overhang). The PV company then came and fitted the trays, cabling and flashing, then the roofers came and fitted the slates, then the PV company came back, fitted and wired the panels, connected things up and commissioned the system.,

I decided not to follow that order, because both I and the PV supplier felt there was a strong risk of the roofers damaging the panels. What we did was fit everything, including the cabling, trays and flashing, then fitted the slates and then the PV company came back and fitted and connected the panels. It worked well, and presented no problems at all for anyone.

Yes, that's probably another reason to drop the UK's non-standard (in global terms) DAB implementation.

I suspect it's down to demand, cost and market needs. You may have a great DAB signal, but it seems that this is far from universal, as I know of lots of other places where DAB is poor to non-existent. One issue may well be that Makita make this stuff for a large market, bigger by far than just the UK, and DAB demand is not that great in other countries where they sell this stuff, so they've probably dropped it as it was costing more than it was worth, to them. DAB receivers cost more than FM receivers, too, so that may well be another reason for them dropping it. They aren't alone, Toyota offered DAB with my last car, but it's missing from my current one, there isn't even an option to add it as they've removed the DAB button altogether. Instead Toyota have upgraded the FM receiver with a diversity system and two antennas, one on the roof, one printed on to the rear quarter light (much better FM reception in poor signal areas, too). I gather other car manufacturers are similarly pulling back from fitting DAB radios as standard, because reception is so poor away from metropolitan areas. The government has walked back from the original plan to close down FM, primarily because DAB has turned out to have major coverage issues, I believe, and that the investment to try and achieve the same level of coverage as FM is just too great. The problem with DAB is primarily the very high frequency, which makes it virtually a line-of-sight only service from the transmitter to the radio. It's very like mobile phones in that respect, so needs thousands of small transmitters, like the mobile phone network, to get good coverage. No one seems prepared to invest in those, so we have lots and lots of reception black spots, particularly at this time of the year when the leaves are on the trees (FM reception here in the summer is far worse than winter - around 1/3rd of my drive over to the new house is plagued with even FM dropping out in summer, yet it's pretty much OK in winter).

Gravity sand filters are really good for this sort of application, and I'm surprised they aren't used more often - yours is the first I've heard of in connection with rainwater harvesting. There are several DIY designs for this type of filter on the web, mainly associated with cleaning drinking water in third world countries. Interesting that the Victorians used them in this application, although I guess it makes sense because quite a few Victorian water works used large gravity sand filters, before the advent of relatively cheap pumps and the switch to pressure filters (we have a pressure sand filter on our borehole supply). There are lightweight filter media around now that are significantly better than sand, as they have a much greater surface area and being much lighter can be cleaned with a relatively low pressure backwash, whenever it's needed.

I think most of it's written up in my blog here. All I have are two wireless room stats, one for setting the heating on temperature and one for setting the cooling on temperature. They are low hysteresis stats, +/- 0.1 deg C, so provide the fine level of control needed to reduce overshooting the set temperature. The manifold is a standard Wunda one with all the ports commoned so there are no zones (no point in zones, as the heat input is tiny, and rarely needed). The Wunda pump set and remote sensing thermostatic valve does a good job of running the floor at a low enough temperature, unlike some others. There's a need for valves to shut switch from heating (where the ASHP heats both the floor and the buffer that pre-heats hot water) and cooling where the ASHP cools the floor but the buffer is isolated. I used motorised ball valves, because they give a guaranteed 100% shut off, unlike most central heating motorised valves that don't close 100%. This is important as you need to be able to completely isolate the warm buffer (35 deg to 40 deg C) from the floor cooling (around 12 deg C for us).

I'd very definitely fit the UFH, no question. In theory we can supply plenty of cool or warm air from our active MVHR (a Genvex with an air-to-air heat pump built in) but in practice it doesn't move enough air to be particularly effective. The UFH is far more effective, although 90% of the time it's used for cooling the floor, rather than heating it. We're in a very sheltered location, cut back into a hill, with the north and lower part of the east elevations protected by a high retaining wall just a few feet away. The house very rarely needs any heat at all, in cold weather the heating might come on for an hour or so every two or three days. We do need a great deal of cooling though. As I'm typing this the underfloor cooling in running and the MVHR air cooling turned an about half an hour ago. The house is just over 23 deg C inside.

Might be because DAB is totally useless in many areas. Around here it's hopeless, we get a weak, but usable, FM signal, but not a hope of either DAB or terrestrial digital TV (or a mobile phone signal, come to that). Since the digital switch over anyone that wants TV has to either go for satellite or, if you're lucky enough to be in a cabled area, cable, as we all lost the TV service when analogue was turned off. When my car was written off a couple of years ago, the insurers gave me a hire car with a DAB radio. It worked within Salisbury and for maybe a couple of miles outside the city, but after that there wasn't even a hint of a signal. The problem we have here is that many the roads and villages are in fairly narrow valleys, and the transmitters are up on the plain above, so the higher the frequency of the transmission the less chance it has of getting down into the valleys. It's the same reason we don't have mobile phone coverage, either.

I've just checked, and the 18mm thick stuff on the fascias is definitely Eurocell. Note sure about the T&G stuff on the soffits, as I can't find any offcuts of that, but would guess it's the same.

I'll go and have a look now and post back shortly - thanks for the reminder!

You'll definitely have a better comfort level with that option, with it taking a lot longer for heat to soak through the insulation because of the longer decrement delay. Handy being able to use the same stuff for internal wall acoustic deadening as well, and the acoustic deadening advantage will be noticeable with the roof, especially in heavy rain where Frametherm or similar will be better at keeping the noise down.

I think I've said this before, but the chap in the next village uses linked IBCs and has just buried them. He fitted standard small drain lids over the top of each one so he can get at the top cap and periodically clean them out if needed. Since they've been buried they've not needed to be cleaned, whereas cleaning was needed regularly when they were mounted above ground.

I've helped my off-grid friend in the next village with his system a few times. After a lot of trial and error he's concluded that the best way to do it is to have an underground tank, so the water stays cool and dark. This pretty much removed 90% of the problems he was having when he had above ground tanks. The other thing well worth doing is fitting a really good filter system on the collector, to keep out as much organic rubbish as possible, as that then removes the food for the bugs to grow on. His system now works pretty well, but he can't use it for his washing machine now (he used to) as the newer machines don't run hot enough to kill the bugs in the rain water and the phosphates in the detergents provide loads of bug food. What happened was that his washing machine got very smelly very quickly. Rain water will contain a lot of faecal coliform bacteria, from all the bird poo washed off the roof, so you need a certain amount of caution as to how you use it. Toilet flushing is fine, but I'd personally not want to use it untreated in a washing machine. You could disinfect the water with a UV unit, but that's costly to run, as it has to be on 24/7, and would defeat any water cost saving.

I fitted one at the top of our soil pipe stack. Made it very easy to run the four waste pipes from the bathrooms neatly.

Point the Welsh Water guy in my direction next time, Nick, I'll give him some pain and grief to make up for giving you bum info.............. To be fair, there were some solvent-containing foams around many years ago, but mainly the two pack stuff, rather than the moisture curing gun foam. They don't attack MDPE, but some solvents can penetrate the pipe and potentially contaminate the water. However, we're talking about minuscule amounts of solvent that were only around very briefly when these older solvent-containing foams were liquid. Once cured the solvents would have dissipated and the contamination risk, very tiny as it was, would disappear. One problem when regulatory bodies start looking at potentially harmful volatiles is that they often fail to take account of their volatility, and make false assumptions about their potential to linger. The worst are all the fear-mongers that keep spreading scares about formaldehyde. The stuff is highly volatile, it evaporates so fast that it just doesn't stay around long in anything that's not very well sealed.

I renovated a pile of old tools I rescued from a bin years ago, that had all gone rusty as the bin was half full of water. I'd chucked them all in an old paint tin, filled it with engine oil and left it (and forgot about it for around 15 years). The tools were good quality (government ones from the 1950s, like King Dicks) and around three or four years ago I found the tin and started cleaning them up. A few minutes with a wire brush in a drill cleaned them a treat and I then waxed them with some beeswax I happened to have around and buffed them. The plain steel handles were covered with black heat shrink sleeving and with a bit of fettling (like sharpening up the various side cutters) I've ended up with loads of really nice to use tools. I'll try and take some photos tomorrow, as I've been using some of them. Some of the most useful are some double lever side cutters and parallel jaw double lever pliers, lovely things that probably cost the government an arm and a leg when they were new.

Normal isocyanate/urethane moisture curing gun foam does not react with MDPE at all. It contains no solvents or other agents that attack polyethylene, in fact the solvents that do attack foam (MEK and acetone) are supplied in polyethylene containers specifically because they do not attack this particular polymer. All gun foam now sold is solvent-free (hence the reason that even kids can buy it). The same is not really true for PVC or ABS, both of which can be attacked by solvents used to clean gun foam (but not the foam itself). EPS will cause PVC to go brittle by promoting the leaching of plasticisers so must not be allowed to come into contact with stuff like PVC insulated cable, but is fine against MDPE. As a general rule MDPE (polyethylene) is highly resistant to practically every organic and inorganic solvent in common use. It even resists toluene. The only solvents that do attack it (but only cheap LDPE containers, by making it brittle , not MDPE or HDPE) are petroleum based solvents, so it's not advisable to store petroleum, benzene etc in LDPE containers or allow it to come into contact with LDPE pipe (not commonly found in water systems, but it is sold by people like John Guest for air systems). Sorry you got bum info, Nick, but my first degree was chemistry, specifically organic chemistry.

Sorry, missed this. The level that Peter W linked to is good value, a well-known brand and accurate (+/- 2mm over 1km when reversed and corrected). When surveying it's normal to shoot angles (in 3D, so levels too) in both directions. So you take a set of readings from point A to point B, then swap over the level and staff and take a reverse reading. You then use an averaging method to correct for errors. The surveying I used to do was down caves, to plot out in 3D where the approximate centre of passages was, with section sketches at each station. A level wasn't easy to use underground, so a lot of the time we just used a short staff and a hand-held sighting compass and inclinometer, together with a Fibron tape. You'd take forward and reverse readings from every station and stick them in a notebook. We used to try and always work in closed loops if we could, often using previously surveyed bits at the start and finish. A correction technique was applied to get the smallest loop closure error and the most common was to use the total least squares method (see here: http://eprints.soton.ac.uk/263855/1/tls_overview.pdf ). There are other methods and for just two points you can average the readings to get a slightly better result. The accuracy given for the level that Peter W linked to refers to the standard deviation using the averaged error between two points, I believe. For site setting out then I suggest that hiring kit to set a few datum points, as already suggested, then using a reasonable (Class 2 accuracy) laser level with staff and receiver, together with a decent surveying tape, will be fine.

The Makita cordless saw eats batteries I've found. Mind you, it's a damned good bit of kit, probably one of the best tools I've bought. I just wish I'd not been daft and chosen to replace my ancient, burned out, Black and Decker with a monster bit of heavy junk from Screwfix, before I realised it was impossible to use and went and bought the Makita.

Neat, so the curved pliers bit does work to tension something, but leather over the sole. Handy having a tool that does more than one thing, saves having to keep picking up different tools.

Fencing? Looks like there is a hammer head to bang in wire staples and the pliers grip is for pulling wire. To tension the wire you grip it and bend it back on itself, using the curve of the grip bit a bit like a claw hammer? Alternatively is there any chance they could be a farriers tool? A combined tool for both banging in and clinching over the nails used to fasten shoes?

These seem to be pretty much exactly the same dimensions as the Makita packs and fit both the tools and the charger in the same way. It's hard to spot the difference. except these are blank on the sides, with no Makita logo.

You're still faced with the very low decrement delay of the Actis stuff and it's near-non-existent acoustic insulation though, both problems that are resolved by using something like Frametherm or similar. You also have the assurance that Knauf (and others) have never behaved as deceptively as Actis have, so are, in my view, orders of magnitude more trustworthy.

I had the same question a couple of years ago, so downloaded the material safety data sheets for the ABS and PVC solvent cement. They both seemed to use the same solvents so I concluded there was no reason for them not to work. In practice they work fine, with some reservations. The FloPlast PVC solvent cement is definitely poorer on any form of solvent joint. The pressure pipe solvent cement I got for bonding together the 16 bar PVC water pipe is far better and I ended up using that for everything. It seems to have a gap-filling capability that the FloPlast stuff lacks and may well be similar to the stuff in the tube Nick described. Having it in a tube would make it a LOT easier to use, mine's in a big tin like a paint tin, and I have to splash a bit of MEK in every now and again to stop it drying out.