Costa Del Slough

[freshy]

Hi All,

 

I thought I would say hello here, I have a plot that's approx 0.22 acre, currently occupied by a bungalow.

 

I've always wanted to build my own home and I'm about to embark on this journey for the first time.

 

There is already permission to build a 4000sqft property on the site however it's not to my taste I'm looking for an architect to help me realise my dreams/ideas.

 

A SIP build does interest me, however due to my circumstances I'm not looking for a complete turnkey build. I'd prefer a staged approach i.e. wind & water tight, then I can proceed as budget allows.

 

Are there any pointers or threads that I can start reading, also anyone else near me done anything similar?

 

Thanks

 

Freshy

 

 

 

 

 

 

 

 

 

 

[Ferdinand]

Welcome.

[Ferdinand]

Try some of the blogs as a good start.

Edited July 13, 2020 by Ferdinand

[freshy]

Thanks Ferdinand,

 

I've been reading up on ICF, I remember talking to Nudura at the homebuilding & renovating show.

 

Seems like I have lot to read up on but I'm I'm liking the durisol since there are a lot of YouTube videos!

 

I haven't appointed an architect as yet so if anyone has any suggestions on some with ICF experience please let me know.

 

Cheers,

 

Freshy

 

 

[Bitpipe]

Greetings, just up the road from you at J8/9.

 

Personally, I would not get too fixated on a build system until you have a design that works for you and your plot - and planning!

 

Pretty much any build system can work with any design whether it's trad brick and block, SIPs, timber frame or ICF. There are cost/time/performance trade-offs between all approaches but I'd work on that as the second step once you have a design, and planning.

 

Post planning, we went round the houses on ICF, SIPs and TF before settling on the latter for above ground as we could guarantee airtightness and insulation with that particular contractor. Basement was cast in situ concrete.

 

The only caveat to all that is if you are planning to do the majority of construction yourself, in which case ICF is probably the best system for 'DIY' (however still a lot of skilled tasks required there).

 

 

[freshy]

Hi Bitpipe,

 

Nice to know someone nearby on here. Thanks for the advice, I will crack on with updating the plans for now.

 

Freshy

 

[freshy]

 

I should probably start a blog, but here is a before picture.

[Russell griffiths]

Any potential to put a couple in there, make some dosh and move on. 

[freshy]

3 minutes ago, Russell griffiths said:

Any potential to put a couple in there, make some dosh and move on. 

There is already permission granted to build a pair of semi's however, we have decided to build a large single dwelling. Our plan is to build & learn, stay put for 5-10yrs, then move further afield and then build a passivhaus where we can retire.

[PeterW]

Only issue with things such as ICF is if you are going down the brick finish route (due to planning) then they are costly and not simple to detail on windows etc and the brick skin needs another foundation plinth which can add cost and complexity. 

[freshy]

19 minutes ago, PeterW said:

Only issue with things such as ICF is if you are going down the brick finish route (due to planning) then they are costly and not simple to detail on windows etc and the brick skin needs another foundation plinth which can add cost and complexity. 

Agree, I've ruled out ICF now. It's most likely going to be traditional brick/block or timber frame/SIP.

[PeterW]

My preference these days is brick and block with a 150 or 200 blown bead cavity. It is quick and easy, and with adequate detailing can be airtight too. It’s also cost effective and a “known method” when it comes to finding trades. 

[joe90]

2 minutes ago, PeterW said:

My preference these days is brick and block with a 150 or 200 blown bead cavity. It is quick and easy, and with adequate detailing can be airtight too. It’s also cost effective and a “known method” when it comes to finding trades. 

+1, my new build is brick and block with 200mm cavity, it’s the attention to detail that makes it “passive” and very comfortable to live in.

[freshy]

5 minutes ago, PeterW said:

My preference these days is brick and block with a 150 or 200 blown bead cavity. It is quick and easy, and with adequate detailing can be airtight too. It’s also cost effective and a “known method” when it comes to finding trades. 

Thanks @PeterW I'll look into blown bead cavity, any recommendations? 

[Gav_P]

5 minutes ago, joe90 said:

+1, my new build is brick and block with 200mm cavity, it’s the attention to detail that makes it “passive” and very comfortable to live in.

That’s amazing, I’d always assumed you had some kind of timber / PIR based structure... don’t know why, maybe because you have something that’s near to passive. 
 

what did you use in the cavity? How did you manage to get the block work airtight? 

[joe90]

1 hour ago, Gav_P said:

what did you use in the cavity? How did you manage to get the block work airtight? 

our cavity was filled with 200mm of dritherm 32 (two 100mm batts), some we’re worried about not having an air gap behind the brickwork but it has a BBA certificate for full fill cavity work. The blockwork was parged with a slurry mix, then cement render then plaster finish. Around timber joists In the brick work the ends were wrapped in breathable membrane and pinned under the cement render, even between floors before the ceilings and floors were installed ( read up about the “Tony tray “as a variation but mine did not create a slip plane.) Cables in walls were sealed at back boxes with silicone. We had a warm roof, lined with 11mm OSB bubble glued together and sealed to the wall with expanding foam. The only leaks found during the airtest were a couple of windows not sealed to walls as well as I would have liked (can’t blame anyone I did this ?). 

Edited August 28, 2020 by joe90

[Gav_P]

Wow.. that nice to know that your level of air tightness can be achieve in a fairly traditional build structure. Just the challenge of finding a suitable builder who doesn’t cut corners every time your not on site ?

[joe90]

18 minutes ago, Gav_P said:

Just the challenge of finding a suitable builder who doesn’t cut corners every time your not on site ?

I was very lucky, our builder was almost as OCD as me, and I was onsite every day (retired) so saw everything that was going on, not that I needed to be with him!!!

[Gav_P]

14 minutes ago, joe90 said:

I was very lucky, our builder was almost as OCD as me, and I was onsite every day (retired) so saw everything that was going on, not that I needed to be with him!!!

Very lucky indeed... my builders approach was a little more carefree, I think he preferred to install the cavity insulation from the other side of the field, like some kind of trick basketball shot. It felt like I had to pull him up on something he’d done wrong everyday.

 

.... still , it did mean I got to learn an awful lot about how not to do things ... in preparation for my next build, which I swore that I would never ever do again ?

[sean1933]

On 28/08/2020 at 11:12, joe90 said:

our cavity was filled with 200mm of dritherm 32 (two 100mm batts), some we’re worried about not having an air gap behind the brickwork but it has a BBA certificate for full fill cavity work. The blockwork was parged with a slurry mix, then cement render then plaster finish. Around timber joists In the brick work the ends were wrapped in breathable membrane and pinned under the cement render, even between floors before the ceilings and floors were installed ( read up about the “Tony tray “as a variation but mine did not create a slip plane.) Cables in walls were sealed at back boxes with silicone. We had a warm roof, lined with 11mm OSB bubble glued together and sealed to the wall with expanding foam. The only leaks found during the airtest were a couple of windows not sealed to walls as well as I would have liked (can’t blame anyone I did this ?). 

 

Hi Joe

 

We have a 200mm cavity (plan to pump in graphite eps beads) and I'm just getting to joist fitting stage and got thinking about this. I like the tony tray idea but slightly apprehensive about creating a slip plane especially as not much load in some places above the floor joists. This got me to concluding that wrapping the end of each joist was the best way to go but now I'm wondering how laborious this is, and how easy it was to achieve. Did you just cut small sections of DPM  or airtight membrane (which did you use?) then tape prior to installation? Once installed did these fold back flat against the wall? I don't suppose you have any pictures - paint a thousand words and all that.

 

Any help much appreciated!

[joe90]

12 minutes ago, sean1933 said:

Any help much appreciated!

Yes it was a faff, I used roofing membrane, no tape, tacked to the blockwork and render over. I sometimes wish I had bolted a wall plate (with slurry mix behind) to the external walls at joist ends and hung the joists from that, less faff and work and only needed on the walls at ends of joists, not internal or side walls . Resin threaded rod into block work will also make it airtight. Yet another method would be using built in joist hangers that hang on the blockwork if the blockwork joint is at the right level.

Edited February 17, 2021 by joe90

[sean1933]

Thanks Joe.

 

I did consider the resin bolted wall plate idea but our SE wanted to start looking at full design and it became a more hassle than its worth discussion/cost.

 

Re the roofing membrane, was this just breather membrane (such as protect vp400 - which I have loads lying around but assumed wasnt air tight)? I must say I get lost in all these membranes and tapes!

 

If you didn't use tapes how did you join the membrane lap from each joist between joists, or was that tacked and rendered over too?

 

 

[joe90]

Breathable membrane is more than airtight enough IMO. Just wrapped around each end then flattened onto wall. As I said before, if I did this again I would use built in  hangers like a friend did.

 

Edited February 17, 2021 by joe90

[SteamyTea]

On 28/08/2020 at 07:46, freshy said:

plan is to build & learn, stay put for 5-10yrs, then move further afield and then build a passivhaus where we can retire.

Why wait, this house will be around for decades.

Aim for an overall U-Value of below 0.15 W/m.K and airthighness of under 0.75 ACH@50Pa (get a test done while you can still fix things, a test us less than a bathtub). 

If you are going for underfloor heating, design in 250mm of I dilation now.

And integrate shade free PV into the roof

 

[Bitpipe]

Timber frame is very attractive due to the speed of getting a weather tight structure erected on site (a few weeks). It can also go up in pretty much any conditions (barring high winds) - mine was built in driving rain in November but 8 weeks from the start, scaff was down and the house appeared finished from the outside.

 

For the novice builder (like me) it also means that you have all of the structural considerations, roof, internal walls & floors, temp stairs etc taken care of by one contractor (some even include the slab foundation).

 

You can order windows and doors in advance off-plan and have delivered to site as the frame is completed plus TF can be a bit easier to adjust (within reason). You can then crack on with first fix in short order.

 

However, airtightness requires the same attention to detail as above, there is nothing inherently airtight about a timber frame. Some contractors will include an airtightness guarantee in their contract. You also need to ensure that follow on trades understand and respect the airtightness layer (not to say it can't be penetrated when required, just needs done with consideration.

 

Cost is the main drawback - TF is always more expensive up front and sometimes overall but I've not seen any analysis though that breaks down how the cost compares over the duration of an equivalent block build  - I suppose the key variable there is time and what that is worth to you.

 

I'd say the second consideration is the exterior skin - as mentioned above, anything load bearing (brick or stone) will require its own foundation and you won't get the same speed of completion. Render, timber cladding, brick slips etc would fix directly to the frame itself or to an outer skin of cement board on battens.

 

From a mortgage and insurance pov, you should have no issues with TF.