Jump to content

Leaderboard

Popular Content

Showing content with the highest reputation on 12/06/16 in all areas

  1. Up here it's not uncommon to nail an old microwave oven to a fence post. Postie will know what to do. Crofters are world leaders when it comes to recycling!
    2 points
  2. I got a lump in my throat reading that.
    2 points
  3. Well guys, as you may know I have taken on a local builder with a good reputation for our new build and didn't even get another quote as he was so highly recommended by many people, even my late mother in law knew their family as "gooduns". Because of personal circumstances I am unable to get to site for a couple of months and rely on the builders sending me photos of the work so far. My wife was able to visit this last weekend and I discovered through her description and photos a few issues that I thought were wrong. So I called the builder and he went straight to site and we discussed the " issues" whilst he was on site. It turns out that I was wrong about some things and others had not been specified correctly at the outset so my mind was put at rest. I then Emailed him to say sorry to be a pain and thank him for being understanding. Here is his reply:- John,No problem at all. We all realise your predicament up there and are only toohappy to help in any way we can. As I have said before, it is your dreamhome that you are entrusting us to build on your behalf, so you should haveno concerns about questioning anything that you don't fully feelcomfortable with, or indeed have a vision of that you need to pass on to meor the men on site.It sometimes gets lost in translation between architect, drawings, customer,contractor and men on site exactly what the final finish product is hoped tobe, so frequent updates, photos and discussions are justly required.I can get an oak lintel, no probs. What sort of size and finish? how lucky am I to find such a good builder, if anybody wants his details ( near Bude) just ask.
    1 point
  4. We've sort of covered this topic buried in various earlier threads, but since I need to use this info for my heating calcs, I thought useful to cover this in a short summary post. Characterising the components of heat transfer across a solid / air surface really does come down to basic physics and we just need to crank the numbers into the two main factors at play in this: Radiation. Any surface is radiating heat but is also simultaneously absorbing similar radiation from everything in line of site. If everything is at the same temperature, then this all cancels out and no net flow of energy occurs. However even with a small imbalance in temperatures, because of the amount of radiation being transferred, results in a net energy flow. The physics depends on the Stefan–Boltzmann law, and when you crank the numbers for a surface at roughly 20°C, this works out at ~5.7 W/m²K. OK, this has to be factored by something called the emissivity which can be as low as 0.03 for a mirrored aluminium surface, but for normal painted surfaces like house walls, it's nearer to 0.9. Also remember that the whilst the area can easily be calculated for very smooth surfaces, any texturing (like clothes or carpet pile) can dramatically increase this. Nonetheless, a good general rule of thumb is to assume 5 W/m²K. Conduction. This is atoms of air bumping into the walls and transferring energy that way. Air, being a gas, is light on atoms compared to the solid wall, and so is a poor conductor, but it is also free to move and so the air region in contact with the wall is continually replaced due to any air movement. Once the temperature difference between the wall and the air is more than a couple of degrees, then the heating of the air itself generates convection and this make the heat transfer even more efficient. However in internal spaces, where there are no major drafts or temperature induced convection differences, this conduction makes a relatively small, say 30%, contribution, and radiation is the dominant component. So a good overall figure for bare surfaces is ~7W/m²K and this is what I use in my active slab calculations. This means that when doing U-value calculations, I can treat any material/air interface as having an effective thermal resistance of its reciprocal, that is roughly 0.15 m²K/W within the R-value calculations. Note that the references often assume some level of internal air movement, and so quote a lower thermal transmittance value of 0.12 m²K/W. Also if the surface includes a reflective / foil layer then the emissivity can drop significantly (though not to the 0.03 figure that I quoted earlier unless a high-spec multi-layered material is used); a typical foil-backed plasterboard might achieve an effective emissivity of around 0.3 which is why this is often quoted as having a transmittance value of 0.4 m²K/W. The bible which gives all of these magic figures is the BRE Conventions for U-value calculations document and the data given therein broadly corresponds to the above. Incidentally the average human has a surface area of roughly 2m², so radiates 5 x 2 x (33 - 20) (=130) watts if naked in a room at 20°C. Clearly the more clothes that you wear, the less your effective surface temperature, and the less your radiant heat losses; so with a light covering and a jumper on the torso, this might drop to 100W or so. This echoes a point made in one of Jeremy's earlier posts: how cold you feel in a house relates to your overall heat loss and in still air maybe 60-80% of this total is due to radiant losses rather than conductive/convective ones. So the temperature of the wall surfaces is just as important as the air temperature in determining this comfort level. Being in a room with walls and air at 20°C can feel just as comfortable as being in a room with walls at 17°C and air at 24°C.
    1 point
  5. I don't know how but I've found whatever clearance was needed. Although first time I forgot to fit the skirting and the second time I forgot the skirting grab adhesive... It's so tight I've had to put an ad hoc V-groove in the 15mm thick skirting to clear the pipe. Obviously I've made the connections loosely but not tightened them or opened the valves. The boiler will have a fit and need bleeding and filling and all sorts. A job for a less cold night.
    1 point
  6. I'm just going to **** it (the brackets) with a big hammer until it all fits
    1 point
  7. I was told that when fixing corrugated sheets if they are above a certian pitch then you fix them in the bottom of the valleys as you can screw it down good and tight without distorting the tins profile, however on low pitched roofs i was told to put the fixings on top and be carfull to not over tighten the screws..... I have done both methods and there is no sighns of leakage after many years.
    1 point
  8. We haven't used a letter box (in our front door) for over ten years. What we have is a post box next to the door. People lift the lid and can drop letters and small parcels in. Works a treat. I will be doing the same in the new house, the only tweak I'd make would be to have a small flag rocker on the lid which tips upright if the lid is opened. That way we can see if the box has been opened without opening the front door.
    1 point
  9. One of my preconditions it to provide an accurate survey of site levels across my site. The last time that I did anything like this was just under 40 years ago as a young Lt. in the Royal Engineers when I was surveying for a road, but that was using a decent theodolite to do cut and full calcs. Nowadays you typically lasers and GPS, but I didn't want to pay a fortune for something that I could do myself, so I reverted to a variant of a technique that the Romans used and that is to use a water level. You can buy them off-the-shelf (e.g. this Handyman Faithfull Water Level 10m/33ft which looks like the first image). However, I decided to hack together my own using a couple of 18" lengths of transparent tube, a garden hose and a couple of steel rulers and black masking tape as per the second. Basically the technique is to leave the chair at a reference datum level and move the ladder around the site. The bottle of water on the chair is to top up the water if any is slopped out. Occasionally, I had to shift the position of the readout tube up/down on the moveable measure (to keep the water column in the transparent section). I just entered both readings in a spreadsheet with reading 1 being the moveable readout at the datum. (This is in row 2, because the headings are in row 1.) So the height formula is just (and copied from row 2 to the rest of the rows): =(C$2-B$2)-(C2-B2) Since my garden hose is about 40m long, I was able to cover my entire site from a single datum, and even where I didn't have line-of-sight. As you can see from the inserts, it is really easy to read out the levels to 1mm accuracy, so even if I was sloppy the entries in this spreadsheet are at most a couple of mm out for the entire site. The one thing that you do have to be careful about is to flush the full length of the hose through before you start to remove any bubbles / airlocks and more importantly to ensure that you don't have one end of the hose at (overnight) air temperature and the other at mains water temperature, as this density gradient can cause a systematic error of a few mm.
    1 point
  10. Im working on a site that has been using them for seven years The earliest ones look as good as the latest Really easy to fix lugs on the side for spacing
    1 point
  11. http://www.ebuild.co.uk/topic/15099-light-weight-roof-finishes-ideas-please/page__pid__114717#entry114717 http://www.athyecoslate.com/
    1 point
  12. Please all, let's not take this useful thread any further off topic. The markets and exchange rates are what they are, and there's nothing to be gained from rehashing the hows and whys of Brexit. Thanks
    1 point
×
×
  • Create New...