Bren88
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@L1 wrote:
Hmmm..Well if lead is too ductile, its been used (traditionally & otherwise) for years, perhaps not on such low pitch. How are you lot managing to get hold of Rheinzinc in such small quantities without a lot of bowing & scraping?
Lead is normally only used for flashing on roofs. It doesn’t have to to large project, or Rheinzinc for that matter. Standard plain zinc sheets can be used. For a simple flat roof it would be childsplay. A sheet metal worker could easily finish the seams on site.
Ok, I was giving this a bit of thought on the way home and have a few loose ends to tie up.
Is it true that a sphere is the more effient shape for heat retention. But this gain could easily be cancelled by the fact that there is alot of wasted space that requires extra energy to heat in the first place.
As for a low energy, not a tag I would give to a building which uses excess concrete. Add to that the unique design and finding a builder is going to be hard, even if you do it is going to cost a bit. And when all that is done going to have to get an Agrement Cert, or get it approved.If the reason you like it is the “round home” aspect, it might be better for you to explore the idea for a cylindric design. With similar floor area a cylinder would take up alot less space and so be a more effective design for heating, adding to that the fact that a cylinder is probably the second most effective shape for heat retention, it just might be a more energy effective design. With a flat roof, cheaper/easier/more enviromental solutions could be used. And you would have less trouble with getting a builder. And obviously you still have the round home you wanted. Let me know what you think.
@popt_art wrote:
1. its decreased surface area requires less building materials.
2. exposure to cold in the winter and heat in the summer is decreased because, being spherical, there is the least surface area per unity of volume per structure.
3. the concave interior creates a natural airflow that allows the hot or cool air to flow evenly throughout the dome with the help of return air ducts.
4. extreme wind turbulence is lessened because the winds that contribute to heat loss flow smoothly around the dome.
5. it acts like a type of giant down-pointing headlight reflector and reflects and concentrates interior heat. This helps prevent radiant heat loss.Some of those reasons are true, but others are slightly twisted to suit the domes.
- A domed roof would have a more materials than a flat or even a pitched of the same height, depends on the design
- Surface/volume agrument is fine, I used it in my last post
- Not sure about that one on a domestic scale, wouldn’t work once the house is fitted. So no difference there
- I can’t really comment on this one, anybody care to share thoughts on the affects of wind
- Would probaby depend on the internal finish, The shape would control where the reflected heat is passed to, but not how much it is reflected
I’d say somr of the points you took from that site relate to “Bucky Fuller and his geodesic stuff” more than domestic scale designs
@a boyle wrote:
……………. i can see no reason why a dome would be any more efficient to a south facing house. ……………….. As a result of being round less of the surface can face the sun at any one time.
It is true that a house that concentrates the glazing on its south facade is going to benefit from solar gains, but it has its limits. A round house would have less solar gains, BUT it would have higher heat retention properties due to the improved ratio of building volume to surface area. Think of the overall heat loss method for calculating proformance of a house. The better the volume/surface ratio the less insulation is required to comply. This improvement would outweight the loss in solar gains i’d imagine, like the way that single glazed windows give better solar gains, but that doesnt come near making up for the fact that they are poor insulators.
Prome wrote:Wood chip/pellet stove – €1,100Wood chip/pellet boiler – €4,200
Wood chip/pellet stove with back-boiler – €1,800
QUOTE]Just out of interest I had a look at the wood pellet angle. I found one company so these prices are my no means the lowest but some costs i found were:
Wood chip/pellet stove – €1,911
Wood chip/pellet boiler – €4,360
Wood chip/pellet stove with back-boiler – €3,733
So a taking away the grant money a stove would cost the buyer €811, a boiler €160 and a stove with back boiler €1,933. Plus installation for all.
Not too bad at all, esp for the boiler or regular stove.@Graham Hickey wrote:
How would you space boarding underneath the zinc Bren88?
A small c.4mm gap is left between the boards and they are fixed to the rafters. That site you posted, VMZinc.com, are another market leader. The following is taken from their website and is on basic structure under a zinc roof.
Clean and dry 100 to 150 mm wide, 18 or 24 mm thick softwood boarding, according to the rafter centres.
Any wood treatment products (fungicides, insecticides) must be dry and completely neutral in relation to VM ZINC®.
The roof boards are fixed perpendicular to the direction of the pitch leaving a 3 to 5 mm gap between them.
They are securely fixed to the structure.
Maximum difference in height of 1 mm between roof boards.
The deflection measured under a rigid 600 mm long straight edge cannot exceed 2 mm in all directions.
The roof board nails are countersunk in order to avoid any contact with the VM ZINC®.@BTH wrote:
However, it’s a pretty awkward system alright – the underside of the zinc has to be ventilated and a lot of control is needed at the joinery stage of the roof construction so that the Zinc contractors can come and do their job properly.
As long as it is detailed right, it can be just as simple at the joinery stage. Using rafters without full fill insulation can be the easiest way to achieve ventilation and use spaced boarding instead of conventional ply under the finish. Decide now before it becomes a problem when you change your mind and you are trying to adapt.
But as BTH said it is more expensive. And as for a lead roof. Don’t even bother. Lead is far too ductile, thats why it is used for flashing.
I’m pretty sure that the diagram your looking for isn’t coverd in the regs as regards stairs, The regs covers heights, slopes and spacings. It is pretty much out of your hands as the “distance required to turn down” is going to be establised by the manufacturer if it is a pre-fab rail.
Is it a timber onsite constructed stairs you are thinking of?@Frank Taylor wrote:
Thanks for all the replies.
One more question: would a basement make a house more susceptible to radon gas? Someone mentioned this to me and I don’t know if it’s true. I’m going to ring the RPI tomorrow and ask for some advice. I’m thinking of building a house with a basement to be used for utilities and extra living space.
A properly contrusted basement is no more affected my radon gas than a regular house, as long as the workman ship and materials are satisfactory. As long as the right membrane is used it will be fine.
@LittleLamb wrote:
Very interesting topic:) I am wondering the Eco-House that Century Homes are selling, is it a passive house? I believe the Scandinavians do passive housing extremely well.
It is the closest to passive that we have here. It contains many of the elements that are in passive houses such as the removal of permanant vents and a mechanical heat recovery system and the sun space.
I haven’t had time to check but did century homes publish heat energy rating figures for their eco house yet. Woiuld be interesting to see how low they have gone.
Have a look at http://www.rheinzink.co.uk/. They do a wide range of products and there is one for every situation.
A 9 degree pitch isn’t that flat at all, zinc can be used on pitches down to 3 degrees and other materials can go to much lower pitchs. For a small job like this zinc would be alot more awkward to use and expensive than membrane sheet/built up layer materials (which are available in a much wider range of colours than in the past).
Why did you choose zinc in the first place? And what’s the span of the roof.It is possible that the vents installed are simply not adequate to achieve the required number of air changes for the room. If the window board requires mopping each day then the mould is going to keep growing and will continue to be a problem.
Can you give a little more detail on the problem, was there no ventilation in the room at all? Vents built-in windows are used to hide large ugly vents, it is possible that the room was design with such vents and at a later stage somebody changed the windows to be used without being aware of what he was doing.
Has the mould started since or before the change was made, and what is the workmanship like on the modification, I know of a similar job where an addition to a job was badly done and left a bigger problem than it was to fix.I well the plans for the house are only released a while, I was at a talk from the the heads of century homes a while ago and they were only finshing the testing of the mock up. But if they reach their expected energy output it would be well worth looking into it. Whats the floor area of the plans?
@maggie wrote:
Also the web-site mentions that the house is completely sealed and uses meachanical ventilation to vent the rooms. This would need to be checked out.
I think I missed your point there Maggie. Why would that need checking. I see no problem with it.
And Prome, the Eco house would be alot cheaper to run, but it will be more expensive. As regards timber vrs concrete, the same level of insulation can be achieved with either, it id just reached in different ways and amounts.
As DJM said 2.4m is the min, and it is fine, but the 200mm (8in) in no harm. But if your going to go for a pre-fab timber construction for the main section (from earlier post). Then it would probably be alot cheaper to use their standard, but still look into it.
As for the floor thickness, the maxium span accross the dining room/kitchen is 5.4m. This is quite a large span and needs joists measuring 75×225. The spacing of the joists would be 300mm (with strenght class 14) or (400mm with C16). In the ground floor bedroom area, a more standard 44×225 jist can be used. You could use more shallow joist need for the short span, but it’s easier to keep ceiling heights the same.
So the floor thickness will be around 260mm including floor and ceiling.If your updated floor plans have different spans in them let me know and i’ll revise the joists sizes.
Comparing number of rooms in a house to the size of the tank required. And then to the number of rooms in your hotel, looks like you’d need a tank around the 4500L mark. Thats just a quick stab, and other things have to be taken into account. I might be way off. But the one you have already is 4500L for a reason.
Well “FallingWater” has survived 70 years. FLWs design built from stone, glass and reinforced concrete. The buildings most impressive feature was the steel reinforced concrete slabs that cantilevered out over a waterfall. The house had structural problems from the beginning. The contractor built the forms for the reinforced concrete terraces without taking into account the fact that even cured concrete sags a bit after the forms are taken away. But the failure of the building is due to the expermental design and not the concrete it’s self. The catilever was too large and the ground wasn’t capable of holding the weight, and so the building was tied back to prevent it from falling. If I remember correctly the water level rised into the house at one time. And it survived that.
Fallingwater is by no means perfect structurally, but I would like to think that we have made some technical advances in the last 70 years.The lifetime of the concrete structure is more important than its strength. Since corrosion is the main cause of failure of reinforced concrete, a corrosion proof reinforcement can extend the life substantially. For these purposes some structures have been constructed using fibre-reinforced plastic rebar, grids or fibres. The “plastic” reinforcement can be as strong as steel. Because it resists corrosion, it does not need a concrete cover of 50 mm or more to protect the steel reinforcement. This means that fibre-reinforced structures can be lighter, have longer lifetime and for some applications be price-competitive to steel-reinforced concrete
@LOB wrote:
Top hung is a bit more susceptible to gravity I would have thought.
Obviously, side hung stay stay open on their own accord. Top hung have gravity to fight, and that’s why they have a different sliding mechanism. One that stays at whatever level you leave it.
Top hung windows remain open just as easily as sid hung.
Top hung are definatly accepted means of escape, in fact the diagram in the regs shows a top hung window.
The company may have being trying to say that you cannot install all top hung windows, as horizontally hung windows on the lower floors below the escape are not permitted.
