saveasteading

Stainless steel screws so they don't rust while the water flows along them.

I'd agree just make a hole in the top. For the overflow it would be simple to add a water tank outlet near the top. First think "what if". If the tank completely fills, where does the water go? If that seems a problem then maybe add a second overflow at the same level or higher. The two can join as the vertical pipe will flow fast. The tank will be green soon. Esp if you paint it with an earth or compost mix.

Perforated pipe with gravel surround will catch this theoretical gas and vent it. A plastic chamber each end. Radon barrier above. Complexity will vary acc to your construction method. I'd have to check why the radon is expected to somehow get through the barrier so needs venting. A holistic solution shouldn't cost too much. OR. Believe the people trying to sell you stuff. I've built about 60??? Buildings in Kent some very near you, but none needed radon measures. I feel that the sales opportunity/ designer caution has increased over time. I'm unaware of any issues arising in buildings without it...eg most of your neighbours. Can you find out what anyone else locally is doing? That will give you precedent.

£1.50/ m2 and no normal dpm needed, or am I missing something?

Radon is simple. Maps show the risk level, by postcode even. If it needs protection it's a standard membrane and easy while constructing. If not, then not. But don't ignore it. Have you tried to put less insulation over your existing slab, and then balance it elsewhere? The rules can be adjusted too, esp as this would be a 'sustaimable' option ie not buying concrete. Are you looking at a few cm of problem or a lot?

A. I simply like to get drains out of the building by the shortest routes and keep things simple. Blockages are findable and outdoors. Also not in the way during construction. B. With a bit of tidying up it works. @Nickfromwalesis saying elsewhere that a flattish fall doesn't need an air admittance valve,and presumably vent, so it's worth checking the regs.

Good move. It will hold it all in place, fill any tiny gaps, stand up to careless feet, but still allow it to joggle if the building moves.

This and other comments re fiddling vat etc. doesn't read well. Most builders will deal with you fairly and legally. Bigger businesses have bigger overheads. Someone organises all this and takes risks. On self build you take on some management and risk. You want to do the windows to save money fair enough. But who's problem is it if they don't fit properly? Who tells the builder the construction detail and openings size? They are wise to add costs for hand-holding and risk. If you are giving this vibe of distrust to potential builders then they will decline, or add money for risk. Dont mess with the VAT. They can spot it and the consequences are serious. In the SE the Labour costs are high. There is plenty of work for small builders, they are being selective and enjoying this period of income along with some power of choice.

From memory only, you need an open stack at the end of the run. AAVs can be used elsewhere. It's all in the building reg's free online. A, with extra chamber on bend , for me too.

So use the equal sight distance principle. eg, if you set the instrument in the middle of the room it minimises errors.

Agreed. A secure store with a padlock on it will be broken into at the levers, causing expensive repair. They are worth buying (used once from china) for any use over 6 months and will be used for material and sundries and for small tools that aren't quite ready to throw away....and that will be left for you.

As @jack says. Watch the 10.30 forecast or equivalent. esp. the pressure chart. Compare the forecast, which is very general, to your own circumstances. You may have influences from hillls etc that give you an island of better or worse rain than even 5 miles away. You will become good at it. The jet stream will become a subject of note. On balance the weather is likely to be much the same as today. Suffolk. My forecast. The winter will be cold and damp.... Dutch weather.

Yes, That was my implication. Velux, Catnic, Readymix, Celotex, and there must be many more I can't think of.

Used rigorously i'm happy it is +/- 2mm, maybe much better than that. That's a hunch, and I haven't checked it against known levels. Where I've had issues was in doing levels over a period of time in hot weather. The tube/gas would be heating up I suppose. I learnt to reset and start again. But doing, say, 20 points around a perimeter wall or over a slab Im very happy with it. Especially that distance is inconsequential. The biggest downside is that it is not compatible with a busy site, as the tube is either in the way or vulnerable. I wouldn't want it in a trench doing drainage for example, with an excavator and shovels and pipes being moved.. But would be happy in the empty trench, setting or checking levels. The biggest upside is the reverse of that. I can quietly do surveys or check other people's work, on my own and at my own pace, with thinking time. An advantage I haven't mentioned is with large height differences. This could be used with the base downstairs and the gauge up a floor or two. eg no excuse for joists being set wrongly. I used this mostly on big projects to set out levels for steel base plates. After 4pm. I could stack shims and recheck them, or write a number on the concrete. Also to check slab perimeters before block or sole plates went in. And if there was any serious doubt about what someone had built, to check it on my own after hours, without creating friction. Very happy with it. Does that help for your own circumstances?

Thats exactly what i have. Mine is about 15 years old.

Interesting. I'm not surprised that Fakro is highly desirable as I never had any problems, but they didn't then have the name. Architects might specify Velux without thought of any alternative. That's quite a price difference / reversal though.

I have one but hasn't been used in 30 years. Pythagoras works more quickly so I DO use 2 x 60m tapes. In case interested. When being trained, they sent us round a housing estate with an optical level, so about 1km and several blind corners. Training was by ex mining surveyors on the basis that they could do it underground and unsighted, so were very good. We had to arrive back at the same hilti nail point with 3mm maximum difference. There was no point in cheating as it was training. Key to success was equal back and fore sights, so any errors cancelled out, and a very distinct surface (change point) to place the staff on.. We would take 6 readings, score out any rogues and use the mean. All done by hand: pencil in a potentially soggy book. The chainman rocked the staff on the point, which made the numbers appear to go up an down, and the lowest of them was the most accurate. In reality, the chain men (young lads really) couldn't choose the good change points so for training it was all Engineers. In real life I once had completely nonsensical numbers. I asked the chainman if there was something wrong with the official point (a metal spike) and he admitted he couldn't find it in the bracken so had used his initiative and put the staff on his toecap. Theodolites for angles.... way more tricky, especially through woodland or over cliffs .. another day. And then there are tacheometers for slope distance and height change. It all sounds very technical but our other main tool was a 14 lb hammer for banging in posts.

I think it is oil. The height difference creates a pressure which is converted into mm. It isn't perfect as i reacts to temperature change and so needs resetting. A water level is absolutely fine, just more fiddly as a one person operation.

The cladding supplier is your best contact. Then it will integrate fully and br the same delivery.. If you had 20 then it's worth shopping around, but not for a few.

We are going for integrated profiled skylights. They fit in with the cladding. They aren't pretty and don't open, but they won't leak, are £300 each, and they are only for daylight in big spaces. It depends if you need them as windows and perhaps appearance.

They do fall apart if abandoned, due to damp mostly. So you must see the cabin or get some comfort on the condition so yours is not beyond that stage. Probably being given away because it is approaching that stage when hirers would complain. The construction is usuallh of ply floor and ply / thin hardboard walls. I've not known any have their primitive windows replaced... there isn't much wall structure to fix to. That said, hiring is very expensive. Buy or take a free one and put it up on blocks with lots of air under. Expect to spend a lot on heating and putting up with summer heat. Keep it in good order and worry about it next life in a year or so.

The main error I have observed is a groundworker holds the staff until the receiver beeps, then as he bends to mark the base level, let's it all move. And they get fling about hence very approximate. They should need compulsory training before buying one.

Yes, the only way I could survey beneath a working pharmaceutical factory with 4ft undercroft an pillars regularly. Yeuch.... all sorts of smelly stuff dripping through. I have a high tech equivalent, a long tube connected to a pressure meter, and giving height difference digitally. Great for working alone when nobody will trip or drive on it, and subtly checking the day's work.

One of my early jobs was setting the line of the A9 using theodolites for line, and optical levels for gradient. Over 14 miles the curvature is significant, but not as much as the hills, woodland and midges.

There is another rooflight manufacturer called Fakro. Polish I think. A fair bit cheaper and still very good. There are standard details for skylights into profiled metal. The detail and workmanship need to be very good as ig us a very vulnerable point, almost like an internal gutter. If the cladding is foam filled then this becomes exposed on the " crowns". You would want to be careful too with where side laps come as you wouldn't want a very narrow piece of cladding.