New Arrival

[MikeSharp01]

I have led such a boring life.... I think I will go and do some building, oh hang on its a Sunday so I will have to do it very quietly.

 

PS Welcome back to THE forum - well on the way now to emulating the hitch-hikers guide to the galaxy of all things " building, renovation and self-build " EG:

 

• "The build hub guide to the galaxy describes forum members as generally somewhat demented humans who have led otherwise interesting lives on the plant earth but have fallen into building what they euphemistically call dwellings on this plant. The members have a number of rituals that must be performed at regular intervals including out boasting their exploits with their partners such as what they did on their honeymoon, (- a short time spent doing stuff you didn't used to be able to do until you were 'married' but which is now so much practised before marriage that the whole idea of a honey moon has, in the opinion of your editor been entirely devalued) and what they gave as gifts for Christmas (- a short lived celebration requiring the giving and receiving of unwanted gifts as a mechanism for rebalancing out the planets mass because it results in lots of objects being moved from on side of the plant earth to the other). Although such dwellings are designed to keep out the weather, ( - a topic often discussed among the peoples of planet earth), they are no defence against the Vogon destructor fleet that is at this very moment receiving orders to clear a space for the pan galactic highway that will involve the planets destruction. Destruction that is only assuming that the galactic planning authority grants the necessary permissions, insurances are in place, the DHW supply scheme is finalised, the bath surround design is complete and all 'party universe' agreements have been ratified - all of which ensures that although the Vogons are ready and waiting with their DIGGER ( - suggestions please) the highway, like so many others planned by the powers that rule the galaxy, will not be built and the forum will carry on productively using up my time ED."

Edited April 30, 2017 by MikeSharp01
Typo

[ToughButterCup]

23 minutes ago, MikeSharp01 said:

I have led such a boring life.... [...]

 - all of which ensures that although the Vogons are ready and waiting with their DIGGER ( - suggestions please) the highway, like so many others planned by the powers that rule the galaxy, will not be built and the forum will carry on productively using up my time ED."

 

Kubota

[SteamyTea]

28 minutes ago, MikeSharp01 said:

DIGGER ( - suggestions please)

https://www.youtube.com/watch?v=tML48HtUIS8

 

[Jeremy Harris]

3 minutes ago, SteamyTea said:

https://www.youtube.com/watch?v=tML48HtUIS8

 

 

I got to stand around 30ft away and alongside from one of those, the Shuttle Crawler, as it was coming back from a launch to the Vehicle Assembly Building.  It's reassuringly large.

[MikeSharp01]

How about: Devilishly Ingeniousness Gargantuan Galaxy Ephemera Remover. (You me, everybody - as nothing on back of the elephant of time.) Back to work - its windy so moving 8x4s onto the roof of the GR is 'interesting'

[DNA]

I've had to go back to work as well chaps.. got 90m of 325mm solid foundations walls to build.

 

Also got a services question for everyone: Anyone run incoming utilities in ducts underneath a block and beam floor before? I cant see why it wouldn't be ok but cant check with utilities until tomorrow.

 

 

[Oz07]

How you doing 325 in block? I was thinking for a job the other month and I thought rather than pay thru nose/long wait for 350mm trenchers it would be easier to lay 3 blocks. 1 on edge, 2 on side next to. Then for next course the same but put the edge block under opposite leaf. Seemed lass faf than filling cavity?

[ProDave]

35 minutes ago, Oz07 said:

How you doing 325 in block? I was thinking for a job the other month and I thought rather than pay thru nose/long wait for 350mm trenchers it would be easier to lay 3 blocks. 1 on edge, 2 on side next to. Then for next course the same but put the edge block under opposite leaf. Seemed lass faf than filling cavity?

That's normal practice for under building here, known as "Block and flat"

[Nickfromwales]

5 hours ago, DNA said:

I've had to go back to work as well chaps.. got 90m of 325mm solid foundations walls to build.

 

Also got a services question for everyone: Anyone run incoming utilities in ducts underneath a block and beam floor before? I cant see why it wouldn't be ok but cant check with utilities until tomorrow.

 

 

I doubt the gas people would be happy, unless it's fully ventilated. 

[DNA]

Hi Guys, well into my blockwork now - see my 'sunset over blockwork' piccy below.

 I went for a 325mm solid wall Oz07 because it was just easier than setting out a cavity wall and then just filling it in. Hardly any price difference really as my cavity has to be 125mm (70mm insulation + the usual 50mm) which is ideal for a 102mm block. Also its pretty much a self regulating size - 102mm block upright + 2 x 215mm blocks on flat as Prodave said +10mm joint - automatic 325mm wall. Next course then just alternate the positions of the two skins for an automatic cross bond.

 

Still didn't get to the bottom of the services under block and beam issue Nick but I suspect your right. I've just left some openings for now till I can confirm it but have to find a way of not putting the meter boxes on the front elevations like the gas and elect installers want.

 

 

[PeterW]

39 minutes ago, DNA said:

70mm insulation + the usual 50mm

 

What insulation are you using as that's borderline building regs values. 

[DNA]

Hi Peter aircrete internal and with 75mm kingspan gives us 0.2 with hard plaster finish. Might move to insulated board if needed but not decided yet. Happier to put my money into high quality triple glazing right now.

[Nickfromwales]

Be VERY particular around the joist sockets if they penetrate the cavity so you reduce draughts as much as possible. Ventilation heat loss will soon negate any benefit your 3G windows offer . 

I'd have a good sit down with your builder to discuss methods surrounding these and other such penetrations, such as soil and wastes etc.

If you look after these things now, it'll serve you very well later down the line. Also, have you considered single room ventilation with heat recovery for the bathrooms?  

[Mr Punter]

On 23/04/2017 at 20:17, DNA said:

All of the seemly ‘reasonable’ 1-2% additions quickly add up. –

 

o   sprinklers (3-4% is nearer the truth)

 

I have just had sprinklers installed in 7 houses.  Total cost £16,950 to cover 1183m2 total = £14.33 / m or £2,421 per house.  Mains fed.

[Jeremy Harris]

36 minutes ago, Mr Punter said:

 

I have just had sprinklers installed in 7 houses.  Total cost £16,950 to cover 1183m2 total = £14.33 / m or £2,421 per house.  Mains fed.

 

 

That's a heck of a lot cheaper than I could find for a single house, 130m².  The best quote I got was for a basic installation cost of £4,200, ex VAT, plus back-up power for the water pump that was going to add around another £2k.  This was for a minimum spec system that the fire officer would accept.  In the end the recommendation never made it into our approval as a condition, but if it had it would have made the build cost greater than the value.

 

I can fully understand the reasoning for sprinklers, in terms of protecting the property, but when talking to the fire officer he was clearly of the view (off the record) that effective alarms were much better, as getting people out of a house quickly was far more important than trying to limit subsequent fire damage to the building.  Had we been forced to fit sprinklers, then I was strongly drawn towards the low water volume mist systems, primarily as they seem more effective and have the big advantages of causing far less property damage and not needing a pump back up power source (they would have worked from the pressurised water volume in the accumulators).

[DNA]

Probably not a bad deal on 7 houses but so much depends on the configuration of the house and its size which affect the number of heads and pipework and mains supply size etc.

 

The trouble with self build is that we often build bigger houses and include more details etc. My manifold cupboard for example would have needed a sprinkler head inside it because one of its internal dimensions was over the 1m limit.

[DNA]

Hi Nick, already on the case with air tightness. I used Manthorpe joist seals in my last build and they worked really well. I tend to add some expanding foam around them when their fitted and then inspect this the next day to take off any surplus that might have pushed into the cavity before we carry on with the blockwork

 

 

manthorp.pdf

[DNA]

Just to thow another viewpoint out there chaps, I'm really concious that a lot of effort is still going into reducing heating costs. However, in already living in my last self-build, I'm seem to be getting more concerned these days oover solar / thermal gain and the need for ventilation/cooling.

 

I have some direct experience. One bedroom in the attic for example, despite loads of PUR is still too hot in summer months and yet the rest of the house is nice and cool because of its heavy traditional masonrey construction.

 

It will be interesting to see if views change before too long to consider how we deal with overheating rather than just reduction in heating.

[Jeremy Harris]

47 minutes ago, DNA said:

Just to thow another viewpoint out there chaps, I'm really concious that a lot of effort is still going into reducing heating costs. However, in already living in my last self-build, I'm seem to be getting more concerned these days oover solar / thermal gain and the need for ventilation/cooling.

 

I have some direct experience. One bedroom in the attic for example, despite loads of PUR is still too hot in summer months and yet the rest of the house is nice and cool because of its heavy traditional masonrey construction.

 

It will be interesting to see if views change before too long to consider how we deal with overheating rather than just reduction in heating.

 

There's your problem! (the highlighted bit).

 

PUR, like most lightweight foams, has a very short decrement delay, so lets a lot of heat through over the course of a few hours.  A structure with a decrement delay of greater than around 5 to 6 hours, but with the same insulation value, won't over heat to anywhere like the same degree.

 

This article discusses decrement delay and its importance for comfort:  http://www.greenspec.co.uk/building-design/decrement-delay/

 

The other factor is solar gain control, and there are several ways of dealing with this.  We fitted solar film to our large, South-facing, glazed gable and it's extremely effective at cutting down solar gain, yet doesn't adversely affect the performance of the glazing in terms of keeping heat in.  You can get glass with this sort of external coating on.  Another thing to look at is designing in external shading for solar gain control, lots of ways of doing it, like a brise soliel or other form of window shading.  Had we been able to get consent from the planners we'd have probably fitted external shutters.

Edited May 5, 2017 by JSHarris

[DNA]

I'll have a look at that article as PUR is probably the default choice on this build too. Looks like I need to read up on the forums again. So what would be better than PUR then .. presumably YBS superquilt or something?

[Mr Punter]

2 hours ago, JSHarris said:

 

 

That's a heck of a lot cheaper than I could find for a single house, 130m².  The best quote I got was for a basic installation cost of £4,200, ex VAT, plus back-up power for the water pump that was going to add around another £2k.  This was for a minimum spec system that the fire officer would accept.  In the end the recommendation never made it into our approval as a condition, but if it had it would have made the build cost greater than the value.

 

I can fully understand the reasoning for sprinklers, in terms of protecting the property, but when talking to the fire officer he was clearly of the view (off the record) that effective alarms were much better, as getting people out of a house quickly was far more important than trying to limit subsequent fire damage to the building.  Had we been forced to fit sprinklers, then I was strongly drawn towards the low water volume mist systems, primarily as they seem more effective and have the big advantages of causing far less property damage and not needing a pump back up power source (they would have worked from the pressurised water volume in the accumulators).

 

Some of these were 4 storey without an alternative means of escape, other than the main staircase.  They share a 50mm main supply, split off to 32mm for each unit.  No pumps or accumulators.  Interlinked mains smoke or heat detector in all habitable rooms and stairwells.

 

In the event that one of the heads is activated, the water released is nothing compared to that from a fire tender. 

[Jeremy Harris]

50 minutes ago, DNA said:

I'll have a look at that article as PUR is probably the default choice on this build too. Looks like I need to read up on the forums again. So what would be better than PUR then .. presumably YBS superquilt or something?

 

Wood fibre, cellulose and similar are pretty good, certainly double or so the decrement delay of lightweight foams, like PIR, PUR or even rockwool.  YBS superquilt is multifoil (a.k.a, snake oil........) and has an even worse decrement delay than lightweight foams, and is not itself a decent insulation material, it relies on sealed air gaps and "proper" insulation in order to obtain the advertised U values.  There's plenty of stuff on the multifoil controversy, so I won't repeat it here, but it boils down to  some extremely optimistic advertising that has already got the manufacturers into trouble with the ASA, and had BBA certification withdrawn from some multifoils, because of a misleading test method that was used.  There is a reasonable case for using a thin reflective film under the slates/tiles, to help reflect back out some of the heat that is radiated from the back of them, but I've not seen any real evidence that it makes a significant difference. 

 

It's better to use a warm roof insulation material that has a high heat capacity, as well as being a reasonably good insulator, as if you can slow down the rate at which the insulation heats up the decrement delay will increase.  The idea is to delay heat getting through until the sun leaves that section of roof, when heat then starts to flow outwards again.

[Ferdinand]

24 minutes ago, JSHarris said:

extremely optimistic

 

Where Jeremy has said "optimistic" some of us might say "overimaginative" 

[Jeremy Harris]

1 hour ago, Mr Punter said:

 

Some of these were 4 storey without an alternative means of escape, other than the main staircase.  They share a 50mm main supply, split off to 32mm for each unit.  No pumps or accumulators.  Interlinked mains smoke or heat detector in all habitable rooms and stairwells.

 

In the event that one of the heads is activated, the water released is nothing compared to that from a fire tender. 

 

In our case we have no mains water, and the assumption is that power will be cut, so the borehole pump will be out of action, hence the need for the backup power supply. 

 

We have accumulators, but they could only deliver a couple of hundred litres, not enough for the number of conventional sprinkler heads.  The fine mist systems use a small fraction of the water volume of conventional sprinklers, so although more expensive, this was likely to be offset by not needing a back up power supply.

 

Having seen first hand the damage caused by sprinkler activation, I'd have to say that I'm not 100% convinced about the damage factor compared to fire hoses.  The building where we had the sprinklers go off needed to be pulled down because of the water damage, anyway.  A bit more water damage wouldn't have changed that at all.  The problem was that it was a timber frame, and the water from the sprinklers soaked the frame and internal insulation, and the surveyors condemned it, on the basis that there was no way to dry the structure without effectively demolishing the building.  It wasn't a house, but a storage building, but was similar in many respects to a timber framed house.  For a non-timber frame structure things might well be different.

 

It's this wide variation in cost and damage reduction that makes me question mandating sprinklers.  I can see applications where they are a very good thing, but equally there are applications where their benefit, in terms of limiting damage to the structure, is relatively small, perhaps non-existent.  The exception would be the small, high-risk area, mist suppression systems, as they do seem to be a very good idea for just about any house.  The cost still needs to come down, though, as last time I looked (around 4 years ago) they were relatively expensive, in terms of the real risk reduction they provided. 

 

Edited May 5, 2017 by JSHarris

[DNA]

I clearly need to read up on what seems to be the dark arts of insulation. More urgently, I'm trying to make my mind up about tetris vs PIR slab insulation over my beam and block. I had already made my mind up on this but insulation pricing is causing a re-think.

 

Any experiences chaps? ....I'm working through a cost exercise right now.