Dee J

Well the Marcrist bit did the job. Using their slower geared drill I would have still been drilling. Lightweight B&D pistol drill and water cooling achieved a good rate 5min/hole. 20 8mm holes in 20mm porcelain and plenty of life left in the bit. Excellent.

Thanks all. The primary purpose is a mix of land registry and land purchase contract. Boundary is agreed on the ground with the seller. Just needs someone to put it on paper... and if I want to get things moving the someone=me. The main plot is defined by existing boundaries, this is for the access driveway only. Anyway, bought an online pdf map, converted to jpeg and filling in using MS paint. Slow and old-school, but no learning curve.

Accessing the hive brain again ;-) I need a large scale map to mark on new land boundaries for land registry and purchase contract purposes (mainly to plot a new fence line). The gold solution is to hire someone to survey the site and produce a scaleable data map which will work with online systems. The basic solution is to use existing bad photocopies and sketch in the reference points and measurements by hand. A good midway solution is what I'm looking for. Purchase a map online and use some common software to mark it up. What format should I get the map in, and what software to use? Thanks Dee

If there is 'cross-talk' between exiting air and fresh air input then either there is a leak within the unit or exhaust and intake are too close together on the outside of the building.

If the artex is to lumpy for skimming then its too lumpy for direct overboarding. Levelled battens would be needed first.

If you're worried about asbestos then get a sample tested. If it does contain asbestos the sealing and plastering is a good fix.... professional removal is very spendy.

If its not too thick, pva it and plaster skim. If it's really ott then replace the plasterboard.

Challenging thought. One long bench will look great, but is it really most useful...... How about several separate dedicated benches. One freestanding heavy one with a big vice. A lower one for machine tools. A classic woodworking bench and an electronics bench with a laminate top set for a good sitting height. Dedicated workstations according to the work in hand.... luxury.

Thanks all. Going to have a chat with an architect tomorrow. Exciting times.

Not looking to make a profit. Just can't afford to lose to much of a limited pot.

Just hypothetical pondering. House retail prices vary according to region. Some of this variation is attributed to land costs. But does that account for all the variation? Ok, labour costs have some regional variance too. I guess what I'm getting at is that in high house price areas, self build houses are more economically viable than in low house price areas. Discuss. Our potential 120sq m project in Cornwall would probably have a ceiling retail value of £300k. Factor in a £90k plot, £12k house rental meanwhile, and probably £15k in surface water management and foul drains leaves £183k to build the house.... £1525 per square metre. Just doable I hope.

Been there, tried that. The lamp bases are one of the plastics that nothing will stick to.

Meanwhile in the day job.... I need to drill twenty 8mm holes in 20mm thick porcelain slabs. Not an ideal situation to be in, The 'professional' slab layers ignored all requests regarding the fixing requirements of the patio lights - so now I need to go for a resin bonded stud system. A cheapo diamond drill (AmTech) lasted for one hole. That's with a lightweight mains drill and plenty of cooling water. Short of buying another 19 AmTech bits.... What does the team suggest....

A big question is whether these guys are self employed independent contractors with their own insurance cover and income tax arrangements - in which case it's just like any other contractor... or if you are employing them directly - when I'm sure you responsibilities will be far greater.

Getting a contractor on board with your design style is a good trick if you can manage it.... but in neglecting detailed drawings what you are doing is trusting your contactor to think and plan all those design details for you, and hoping that they have taken on sufficient data that everything works out for all the trades. What you have there with your contractor is a project manager, architect and structural engineer rolled into one.

So much routine plan stuff seems to be on the basis of 'here's the general idea - insert standard details as necessary' - which is fine for traditional pattern housing. As soon as anything departs from the norm then details are often sadly lacking - and are made up on the fly by the project manager and the contractor.... resulting in cold bridges, mis-alignments, re-work etc. Seen it too much on projects where I'm the electrician. Now need to avoid it on my own project.

A few years ago I did some contract work for a microelectronics company. One of the items under development was a super sensitive electric field sensor - real see-through-walls stuff. But the data needed a lot of processing to interpret the results - hence the phone/app link. So when their demo shows a clear image of a pipe or stud, that's not the actual thing you're seeing it's showing you a stock image based on an interpretation of the data... i.e. sensor produces data. data is interpreted as 'vertical plastic water pipe'. phone screen displays stock image of 'vertical plastic water pipe'. For data that doesn't fit a known shape or material you just get a representation of the raw data - hence the animal shows as a splodge, not a photo or x-ray image. So yes it can work. but what happens if you have foil backed plasterboard, or bubble-foil insulation or damp concrete block rather than nice clean plasterboard may be a different thing.

Inside a house, with all metalwork and services bonded, there is an equipotential zone. The cpc of your kettle and the bonded water tap have a guaranteed low impedance connection between them, holding fault potential less than 50v. Outdoors no bonding applies. So the metal case of your welder could, under network fault conditions, be at lethal potential wrt the gatepost you're about to work on. Ok its all belt and braces. Sites should use 110v balanced supplies, but the dno are providing a 230v supply and must make that as safe as possible. Also note your 'safe' 110v transformer isolates you from incoming L & N, but centre references the 110v to the incoming earth. If the PME earth wanders off to dangerous levels, so does your 'safe' 110V. HTH Dee

Not at all. The TN-C-S figure is misleading and is a function of the neutral connection. Lose the N further up the line and the results can be lethal... and no protective trip will operate. With a local TT earth, no influences external to the site can cause it to rise to dangerous potential. Local site faults should be quickly isolated by the RCD.

PME earth has the neutral and earth connected together... and earthed to rods at multiple points on the distribution network. Generally ok until there is a neutral cable fault and local load and fault currents pull local customer earths more than 50v from true earth. If you are in an equipotential zone (services and steelwork all bonded) then the danger is reduced. But outdoors, 'pme earthed' metalwork may present a shock hazard. Caravans are TT to protect people outside them. Site supplies are also TT to protect workers holding earthed tools whilst standing on mud. Hope that helps.

Thanks. All adds to the picture. It's a long way up this learning curve ;-)

You'd have to select your LED power supply with care though. The cheap ones throw out masses of RF noise - so it might slow up the data rates.

Plastic plumbing is excellent for retrofit on old properties. Long continuous runs can be threaded through existing structures. But... it moves a lot with temperature - so always allow for movement when installing. Copper is much better for neat compact plumbing under sinks and in cupboards. Pushfit copper works ok, but is expensive... soldered sub-assemblies can be put together on the bench then fitted in place with pushfit - a good compromise.

I'm still learning a lot about modern house build systems... so perhaps you might help me with what might be blindingly obvious... Your house structure is built on an insulated slab within an insulated perimeter. The house structure sits on this slab - presumably with its insulated portion sitting over the perimeter slab insulation to ensure continuous insulation. So do you have some foundation system outside the insulated envelope to support that brick and flint? Did you have some trench foundation for that section in place before the insulated slab went in? Thanks.

Thanks. Initial contact made and sounds positive. Lets see how things progress.