which way to build?

[newhome]

7 minutes ago, lizzie said:

Majority of members are TF...the forum is promoted by TF manufacturer which is why so many find their way here I suspect.  TBH my brick and block house may not have been as thermally efficient but somehow I liked the feel of it better than the TF.

 

I don’t think that’s representative of the results from this (albeit small) poll. Mine is TF but I found it via Google 

 

 

[Jeremy Harris]

10 minutes ago, lizzie said:

Majority of members are TF...the forum is promoted by TF manufacturer which is why so many find their way here I suspect.  TBH my brick and block house may not have been as thermally efficient but somehow I liked the feel of it better than the TF.

 

 

Just to be absolutely clear, this forum HAS NO CONNECTION WHATSOEVER WITH ANY COMMERCIAL ENTITY.

 

BuildHub is not connected with any supplier, builder, manufacturing company or whatever, and is run completely independently, by an association of volunteer members.  Anyone can help run this forum, and the minutes of meetings, etc are available for inspection on request.

[Moira Niedzwiecka]

@lizzie Your house is so stunning I didn't notice any cracks.

My house was up for well over a year before it was boarded & plastered, maybe that is why I haven't had any, yet.

My joiner friend said after a cycle of all 4 seasons it has mainly settled.

 

One thing I would reconsider if I was ever mad enough to do this again is not to have the internal window frames in RAL 7016.

It has been a bugger where the white walls meet them to get a really crisp, totally even & neat junction.

I have achieved it but it was a real pain.

Mind you, may not be an issue if a professional decorator was involved.

Alas, that was not possible on my budget.

 

[Jeremy Harris]

11 hours ago, scottishjohn said:

If you insist that the air is not cooled then you do not have big enough ridge vents  thus  stopping circulation 

you can,t re invent physics to suit your argument --hot air rises -fact 

ambient air temp in uk has never been at 45c  never mind 55 c 

 so how hot would it be if there was no draft upwards  of this hot air?

 

 a lot hotter and therefore that would transfer even more  heat  to the  fabric of the roof  than it does now .

a larger gap and more air flow must lower inner roof temp 

I suggest you put a probe directly onto the outer roof surface  at same time and see the difference .

you only need look under the bonnet of a car and you will see heat shields working on exactly that principle on exhaust manifolds 

or any sort of finned heat exchanger -by your thoughts they would not work -- 

eg your your air source heat pump--?

air passing a solid surface will move heat 

 

 

First off, we have ridge and eaves vents.

 

Secondly, I do have a temperature probe in the void, and have measured the slate surface temperature, so these are reasonably accurate figures.

 

There is certainly hot air circulation in the void, but as I mentioned before, air has a very low heat capacity so this circulation doesn't move much air (same reason that warm air heating in a house needs either large ducts, or a near-passive level of insulation and airtightness).

 

 

[lizzie]

@JSHarris I never said it was.  I said it was promoted by a TF manufacturer and it is clearly listed on their web site under useful links.  I was given the BH details by this manufacturer in the very early days of talking to them, at least a year before we ended up going with them.  It was intended by them to be helpful information to a prospective customer and it was otherwise I probably would not have found the forum not being a habitué of internet forums generally. TBH I thought it was their forum for the first 6 months or so  but realised before I went with them that it was not so it did not influence the choice of TF provider.

 

What is wrong with linking and promoting?  If other manufacturers had the same links with BH then there would be a wider spread of people -  as it is an awful lot come and look via the TF manufacturers link. Maybe people who use other manufacturers for their TF or other build methods should ask their providers to link to BH in the same way.  Might attract a wider spread then.

[scottishjohn]

slightly different -

-but if you had a air pump connnected to void -- could it be be used as a suppliment to other dhw  or UFH heating through a suitable heat exchanger ?

theres one to ponder  in the search for free energy ?

I know hot  my garage roof gets even on normal days 

 

 

[Jeremy Harris]

8 minutes ago, lizzie said:

@JSHarris I never said it was.  I said it was promoted by a TF manufacturer and it is clearly listed on their web site under useful links.  I was given the BH details by this manufacturer in the very early days of talking to them, at least a year before we ended up going with them.  It was intended by them to be helpful information to a prospective customer and it was otherwise I probably would not have found the forum not being a habitué of internet forums generally. TBH I thought it was their forum for the first 6 months or so  but realised before I went with them that it was not so it did not influence the choice of TF provider.

 

What is wrong with linking and promoting?  If other manufacturers had the same links with BH then there would be a wider spread of people -  as it is an awful lot come and look via the TF manufacturers link. Maybe people who use other manufacturers for their TF or other build methods should ask their providers to link to BH in the same way.  Might attract a wider spread then.

 

Lots of websites link here, including my blog, which gets hundreds of hits a day, so has probably directed as many people here as any other other website.

 

BuildHub has absolutely no control over who chooses to add a link to this forum.  Anyone can post a link anywhere and we would be none the wiser, as it's impossible to even try and control who chooses to do this. 

 

 

[Jeremy Harris]

13 minutes ago, scottishjohn said:

slightly different -

-but if you had a air pump connnected to void -- could it be be used as a suppliment to other dhw  or UFH heating through a suitable heat exchanger ?

theres one to ponder  in the search for free energy ?

I know hot  my garage roof gets even on normal days 

 

 

 

It's been looked at, but the combination of the very low flow rate of air in a roof void, plus the low heat capacity of air, makes it challenging.  One company came up with a combined direct exchange evaporator panel (rather like that used by the Portuguese/Spanish hot water heat pumps) connected to the rear of PV panels, that were in-roof mounted.  The idea was to both cool down the rear of the PV panels, to increase their output, and extract useful heat for heating and hot water.  The problems with this were the price and the need for a massive heat dump outside the house to get rid of the excess heat, as once the hot water is hot the heat needs somewhere else to go.

[newhome]

15 minutes ago, lizzie said:

What is wrong with linking and promoting?  If other manufacturers had the same links with BH then there would be a wider spread of people -  as it is an awful lot come and look via the TF manufacturers link. Maybe people who use other manufacturers for their TF or other build methods should ask their providers to link to BH in the same way.  Might attract a wider spread then.

 

I guess not all suppliers want to be associated with an internet discussion forum. This forum is fairly straight talking I believe, with real world experiences reported by its members, and there are posts praising certain materials, designs, suppliers etc and others where the opposite opinion / experience is true. Most suppliers don't want the balanced, 'real world' view I guess. They want you to believe what's written in their marketing brochures.  

 

There is an advert going up (or has gone up) in the Self Build Centre in Swindon as a way of making the forum more visible to prospective self builders. That said our membership is growing pretty quickly now so clearly people are 'finding us'. 

[scottishjohn]

15 minutes ago, JSHarris said:

 

It's been looked at, but the combination of the very low flow rate of air in a roof void, plus the low heat capacity of air, makes it challenging.  One company came up with a combined direct exchange evaporator panel (rather like that used by the Portuguese/Spanish hot water heat pumps) connected to the rear of PV panels, that were in-roof mounted.  The idea was to both cool down the rear of the PV panels, to increase their output, and extract useful heat for heating and hot water.  The problems with this were the price and the need for a massive heat dump outside the house to get rid of the excess heat, as once the hot water is hot the heat needs somewhere else to go.

not sure that exactly what i was meaning

 but i take your point

if you ducted ALL the air from the roof void ,not just from behind Pv panels that would be a large amount of air+ heat  -

-maybe to input of ASHP --that would lift your  COP   with twice the inlet temp as an average ,obviously there would have to be a cold weather bypass 

and i ,m not totally convinced temps in uk are comparable with southern  europe ,so heat dumping  might not be a great problem  ,

could make high temp ASHP very much more economic  and more suitable to charge sunamp etc ?

certainly with roof mounted/ highwall mounted ASHP  so ducting is short 

Edited April 26, 2019 by scottishjohn

[ProDave]

I am not aware this forum is "promoted" by any TF manufacturer.  Yes a lot of people on here build in various forms of TF (and there are a lot of different variants to TF) but there are also a lot building with various types of ICF or insulated brick and block cavity systems.  Equally there are a lot of different foundation systems in use by members on the forum.

 

 

 

[joe90]

1 hour ago, scottishjohn said:

so far this thread is just being visited by TF  people 

no one with other build choice  anything constructive  to contribute ,

or even pull holes in TF  method  and why  they did not go TF 

 

 

Although I like woodwork and have many woodworking tools we wanted a “cottage” in brick (although most houses round here are rendered and the planners like “sameness” so had a fight on our hands) I liked the quick erection of TF and having visited @JSHarris was mightily impressed with his build. I also like heavy houses (phew, nearly said thermal m##ss?). We are very lucky that a local builder with a very good reputation gave me a fixed price on brick and block to my specification (passive principle) with me doing all the timber work, roofs, floors, windows etc. ( my second cancer put paid to me doing the roof tho ). What I like about brick is its lack of maintenance and “cottagey” look. I have nothing against timber frame and I suppose I could have had one with a brick skin but the sums did not add . I am extremely pleased with our build and we have very little in the way of cracks, just windows cills shrinking a little. I did pay a decorator to paint and he commented that our build had fewer cracks than any other new build he has been on ?

 

Just had some bad news, the bricklayer who did such a good job and has become a good friend has just had a stroke, he is 6 years younger than me, fit as a fiddle, ex military, does not drink (much). So today’s motto is live life to the full, life is not a rehearsal, we are only here once so enjoy it.

Edited April 26, 2019 by joe90
Ass

[joe90]

Regarding cracks, here is my tip fir the day regarding wooden windows. I built angled reveals (cottagey) and suggested the plasterer put a stop bead next to the wooden window, filled with non setting mastic to stop any cracking, he said it was not required......I wish I had insisted.

[Jeremy Harris]

4 minutes ago, joe90 said:

Regarding cracks, here is my tip fir the day regarding wooden windows. I built angled reveals (cottagey) and suggested the plasterer put a stop bead next to the wooden window, filled with non setting mastic to stop any cracking, he said it was not required......I wish I had insisted.

 

We have cracks just like those around our frames, too, where the plaster has shrunk back from the frame edge as it's dried out.  I've been going around raking the cracks out and filling them with flexible acrylic sealant, but it's a messy job to do and would have been better done as you suggest.

[joe90]

Yup, ain’t hindsight a wonderful thing, I did use a stop bead on the porch I built and it’s not happened at all. Going to do the same in the conservatory (if I ever get round to finishing it ?).

[Simplysimon]

On 25/04/2019 at 12:47, scottishjohn said:

blown cellulose insulation --how is ti stopped from gradually moving down the cavity and compacting?

 

when it's pumped in at 50+ kg/m2 it won't settle much

[Jeremy Harris]

2 hours ago, Simplysimon said:

when it's pumped in at 50+ kg/m2 it won't settle much

 

 

Yes, it seems to form a very solid block inside the wall.  I cut a hole for a duct near the top of one of our walls, and this is what it looked like after I'd used a jigsaw to cut a 150mm diameter disc from the inner board layer:

 

[pulhamdown]

On 04/04/2019 at 16:43, Ralph said:

 

Now that it is interesting. I'd not really thought much about solar gain, NE Scotland not been known for the sun but we have a reasonable amount of glass so I better look into it. Thanks

Don't underestimate solar gain, even in NE Scotland.  We have a lot of glass, face SE, but only have issues with bedroom overheating in the summer.   1 1/2 storey TF.  Late afternoon and evening purging usually sorts the problem.  But I find it's my wife who is much more sensitive to hot and cold!   

[Ralph]

3 hours ago, pulhamdown said:

Don't underestimate solar gain, even in NE Scotland.  We have a lot of glass, face SE, but only have issues with bedroom overheating in the summer.   1 1/2 storey TF.  Late afternoon and evening purging usually sorts the problem.  But I find it's my wife who is much more sensitive to hot and cold!   

Definitely something to look at especially after last summer. I'm not a fan of heat, in our last place my wife would have the woodburners at either end of the house going and me and the dog would be by the front door just about passed out. 

[Stones]

We built our house with ICF.  I was very fortunate that there were two contractors well practised in using ICF so was confident in moving away from timber frame (both open and closed panel) which I had previously built with.  I certainly don't regret switching to ICF, and wouldn't hesitate to build with it again in preference to timber frame. Our vaulted ceiling is insulated with a combination of earthwool between and Kingspan across the rafters.  Had I known that a local contractor was obtaining the relevant equipment, I think I would have been very tempted to use on site spray foam insulation.  Unfortunately for us, we were too far along when it became available locally and any benefit would have been far outweighed by the cost and hassle of unpicking work that had already been done.   Anecdotal I know, but our neighbours house is built used a closed panel TF system.  Similar sized houses, insulation levels the same (or actually higher for the TF), similar amounts of orientated glazing for solar gain but out heating costs our lower, and we seem to have a more stable internal temperature (appreciate there are many more variables which could effect this). We've always built using a main contractor, and I wouldn't change that route as for us, it has represented the best balance between cost / time/ quality.

 

In terms of the house itself, I will in due course be posting a full blog entry on the topic of what went well, changes we would make etc.  In summary, and in the absence of a whack more cash, there is very little we would change - some minor tweaks to the layout of the bedroom section, perhaps not improvements, better described as alternatives.  One thing I do regret is keeping glazing to the north side of the house to a minimum - the decision being based on both heat loss concerns and more importantly, that we anticipated the view wasn't going to that good.  As it turns out our landscaping really opened up the view such that I think we probably should have had double rather than single windows to bedrooms two and three, and indeed probably put windows in our bedroom on the north side (albeit this would have increased glazing costs overall).  Lots of positives I could point to, but the stand out for me is the preplumb ASHP heating / DHW system we went for (Mitsubushi Ecodan) - auto adapts to what is required and works flawlessly with zero input from me.  I am however less impressed with our MVHR unit (Vent Axia) and would probably go for something else if doing it again.

[Russdl]

On 27/04/2019 at 19:30, Stones said:

I am however less impressed with our MVHR unit (Vent Axia) and would probably go for something else if doing it again.

 

I'm in the process of choosing our MVHR unit and whilst scouring this resource for insight I found the above comment from @Stones. 

 

Stones, would you elaborate on why you would look for something other than the Vent Axia if you were to do it again?

[Stones]

@Russdl Noisier than units I've had from other manufacturers (albeit that could be the radial type ducting being the problem), collection of condensation in core (which I've not had in previous units, but again, may be due to our marine climate) but most importantly, feel the quality of the outer body (plastic) and the screws / fixing points that fix the front and back panels to the main body are flimsy and break easily (I think @Declan52 has experienced breakage of a fixing point as well).  Plus point is the variable auto boost adjusted by humidity sensor.

[Declan52]

I think I have broke maybe half of the plug type things the bolts that hold the front panel on attach to. They are a very flimsy piece of metal with  threads to hold the bolt that more or less just sit there in a plastic slot. It would have took very little effort or cost to change these to some sort of proper fixing method. 

I have a nut wedged into the slot that will take the bolt but if the plastic slot breaks then I'm probably going to have to use something as basic as a few luggage ratchet straps to keep the front cover on. 

It would be my only issue with it. 

[Russdl]

@Stones @Declan52 thanks for that feed back, it seems more  'quality' issues than 'performance' issue then.