Mitigating Risk With Upfront Payments To Timber Frame Companies?

[TonyT]

Me and my joiner built our timber kit,

I don’t see any less quality, it’s just cutting with a chop saw and nailing with a nail gun.

Get a bench set up and away you go

 

 

[IanR]

On 27/06/2023 at 10:30, Furnace said:

Wilkinson/Touchwood came back with a similar price.

 

Glad to hear the Wilkinson's are still building houses, their social media presence has gone quiet of late.

 

5 hours ago, Furnace said:

My thinking is on a modified stick build like @IanR did with Cullen/Wilkinson/Touchwood where an Airfix Housefix model is produced from a CAD design in a matter of days and delivered to site for erection. The credit risk is far shorter, and the amounts smaller.

 

I can't remember the actual payment schedule for Touchwood, but I felt it lowered the risk as much as possible. The initial deposit covered the CTD Frame design, Touchwood's input to the Frame design, Structural Calcs and the PHPP analysis (if you go all in). If it all goes wrong after, you still have the frame design, including cutting list, structural calcs and a comprehensive set of erection drawings. The next payment is to cover JJI fees for supplying the semi-cut frame and it's delivered directly to your site, so doesn't sit in anyone's warehouse. The Frame is ready for delivery a few weeks after the payment and JJI is a big firm. The next payment covers the Wilkinson's erections costs, and they'll be on site to receive the JJI delivery. The last payment is made as they finish. If you include MVHR design and install from them I guess there's an upfront payment for that also.

[Furnace]

47 minutes ago, IanR said:

I can't remember the actual payment schedule for Touchwood, but I felt it lowered the risk as much as possible.

The schedule is quite granular and leaves little exposure, plus they are open to suggestions about risk mitigation.

[Nickfromwales]

47 minutes ago, IanR said:

Glad to hear the Wilkinson's are still building houses, their social media presence has gone quiet of late.

I was on site with Adam yesterday. He's Wilkinson Passiv Homes now IIRC.

 

https://wilkinsonpassivhomes.co.uk/

 

Great guy, excellent work ethic, and cries himself to sleep if he doesn't get an airtight score that's under 0.2 ACH , (which he does, btw). I am looking forward to working with him on our clients new PH certified build, where I was getting more orange by the minute laying the bloody UFH pipes over fresh rusty rebar (😭). 

[IanR]

4 minutes ago, Nickfromwales said:

Great guy, excellent work ethic, and cries himself to sleep if he doesn't get an airtight score that's under 0.2 ACH , (which he does, btw). 

 

Absolutely agree. 0.2ACH is his target, sub 0.1 ACH on mine.

[Furnace]

1 hour ago, Iceverge said:

What about the stick frame are you worried about?

I think the devil is in the detail, particularly so for Passive House, therefore I'd like to de-risk the critical fabric part of the build. Cullen design a frame that is precision produced in component form and each part locates in precut recess to ensure precision during assembly. I believe this level of accuracy is what allows excellent airtightness without a huge amount of skill. I'm not sure it could be as easily achieved with a 'cut on site' approach.

[Nickfromwales]

Just now, IanR said:

 

Absolutely agree. 0.2ACH is his target, sub 0.1 ACH on mine.

He says he wants a zero before he snuffs it. He'll probably die with a roll of AT tape in his hand.

 

If anyone is looking for risk mitigation, I very much doubt you'll find a guy with more integrity than Adam. He can also stick-build in sites with zero access, which is a huge USP. I have already recommended him to one of my new clients from the Build It Live show at Bicester, as they have a difficult site.

I told Adam, he said "Thanks", LOL. I am sure that, deep down, he enjoys the adversity  

[Nickfromwales]

2 minutes ago, Furnace said:

I think the devil is in the detail, particularly so for Passive House, therefore I'd like to de-risk the critical fabric part of the build. Cullen design a frame that is precision produced in component form and each part locates in precut recess to ensure precision during assembly. I believe this level of accuracy is what allows excellent airtightness without a huge amount of skill. I'm not sure it could be as easily achieved with a 'cut on site' approach.

I couldn't disagree more. You're logic is flawed here, I'm afraid.

[Furnace]

3 minutes ago, IanR said:

Absolutely agree. 0.2ACH is his target, sub 0.1 ACH on mine.

I chatted to him a couple of weeks ago, and was very taken with his approach and integrity. They don't take on too much work in order to ensure high standards can be achieved. He remembers your build.

[Nickfromwales]

1 minute ago, Furnace said:

They don't take on too much work in order to ensure high standards can be achieved.

 

4 minutes ago, Furnace said:

I'm not sure it could be as easily achieved with a 'cut on site' approach.

  

7 minutes ago, IanR said:

sub 0.1 ACH on mine.

   ?

[Furnace]

1 minute ago, Nickfromwales said:

I couldn't disagree more. You're logic is flawed here, I'm afraid.

In what way Nick? AFAIK Adam uses Cullen (or Cullen style) kits and his wealth of experience to achieve his exemplary results. Are these results readily achievable by on site cutting by those not experienced in PH?
I'm a newbie here, so keen to learn from others before I spend money discovering it the hard way?

[Nickfromwales]

1 minute ago, Furnace said:

In what way Nick?

Any detail for ANY part of the build is down to;

1. The individual(s) you select to undertake the work
2. Their (proper) understanding of what you wish to achieve
3. Their ability to execute the work to the required standard.
4. Their tenacity; to research, learn, adapt & overcome.

This is why I am a very busy bunny, as I cannot do a bad job and the results I attain speak for themselves.

You can build your house with broken pallets, it matters not one bit, as long as the person in charge of AT detailing actually give a feck.

Anything can be achieved if you employ the right people. The products, and installation instructions, are available at glance, so educate yourself as to how these need to be implemented, or employ someone to act on your behalf.

The best diligence is your own

[Furnace]

4 minutes ago, Nickfromwales said:

Any detail for ANY part of the build is down to;

1. The individual(s) you select to undertake the work
2. Their (proper) understanding of what you wish to achieve
3. Their ability to execute the work to the required standard.
4. Their tenacity; to research, learn, adapt & overcome.

This is why I am a very busy bunny, as I cannot do a bad job and the results I attain speak for themselves.

You can build your house with broken pallets, it matters not one bit, as long as the person in charge of AT detailing actually give a feck.

Anything can be achieved if you employ the right people. The products, and installation instructions, are available at glance, so educate yourself as to how these need to be implemented, or employ someone to act on your behalf.

The best diligence is your own

Gotcha. Thanks

[Nickfromwales]

1 minute ago, Furnace said:

Gotcha. Thanks

I forgot;

5. Keep asking questions here  

[Furnace]

4 minutes ago, Nickfromwales said:

Keep asking questions here  

Deffo!

 

[Iceverge]

The big risks for passive house IMO are. 

 

1. Airtightness

 

We (me mostly , Mrs and my bro) did this on our masonry build. Zero experience. 0.31 ACH.  DIY blowerdoor really helped too. 

 

2. Continuity of insulation. 

 

Blown in beads for us. No gaps. 

 

3. Thermal Bridging

 

Tricky in a cavity wall but I did the best we could. 

 

 

 

For a TF house I would always suggest pressure blown in dense pack cellulose. This will sort the continuity of insulation. If you blow it in behind a transparent A/T membrane you can actually check this prior to boarding out. It also really helps with airtighess. I don't know if any sub 0.2ACH ratings without it. 

 

Then couple this to a layer of EWI on the TF. Woodfiber boards, rockwool frontrock or EPS(moisture calcs dependant) would work really well. By lapping the insulation over window and door frames you will get superb thermal bridging figures. 

 

So in short my suggestion,

 

15mm fireboard. 

47*44 mm service cavity with Rockwool batts. 

A/T membrane. 

220*44mm stick build timber frame with cellulose blown in.

OSB racking. 

EWI 

Cavity

Rainscreen. 

 

 

Edited June 28, 2023 by Iceverge

[IanR]

1 hour ago, Furnace said:

In what way Nick? AFAIK Adam uses Cullen (or Cullen style) kits and his wealth of experience to achieve his exemplary results. Are these results readily achievable by on site cutting by those not experienced in PH?

 

I'm not sure I'd call what Touchwood/WilkinsonPH/Adam provides a "kit". Some of the I-Joists do come pre-cut, but many don't. To me it is a stick build, just goes up very fast with minimal waste on site. There is a charge for JJI to pre-cut the joists, the decision on what is cut and what is not is down what is most cost effective. Yes, sole and eaves plates are pre-machined with a 3mm notch at every upright position, so that when the frames is going up there's a lot less measuring (once the sole plates are down) and each upright is just slotted into position.

 

What is remarkable, is the AT achieved without any air tightness membrane, and there is no separate vapour barrier. The wall and roof build up is very simple. The air tightness results come partially from the detailing of the external fibreboard layer at the CTD stage, partially from Adam's "tricks of the trade" and liberal use of non-curing butyl adhesive on the external layer and partially from the blown cellulose fibre insulation.

[Nickfromwales]

1 hour ago, Iceverge said:

So in short my suggestion,

 

15mm fireboard. 

47*44 mm service cavity with Rockwool batts. 

A/T membrane. 

220*44mm stick build timber frame with cellulose blown in.

OSB racking. 

EWI 

Cavity

Rainscreen. 

I would, personally, forgo the IWI and EWI, and just employ a 300mm(or more)  twin-wall, a-la MBC ( Larsen?), and kill a few birds with one stone. The electrical and plumbing 1st fix become a ball-ache if the service battens have insulation between them.

I was having this exact conversation with Adam yesterday, and, IF, I have successfully worn him down sufficiently, this project will see 50mm timbers tagged onto internal face of the 400mm I-beams to allow for 450mm of Warmcell in the frame; negating any IWI or EWI whatsoever.

Labour costs, time, and materials costs should be significantly reduced with this approach, so I will be happy to see where these talks end up.

Every day is a school day, so I am happy to be educated  

[Nickfromwales]

9 hours ago, IanR said:

liberal use of non-curing butyl adhesive

That stuff is straight from the deepest depths of hell. Iirc Impey or Wedi sell it for sealing around their wet room shower formers and it is just such a PITA to remove from yourself, your tools, your hair (when you forget it’s on your hands and you scratch your head, pondering how to get your Stanley knife down from the ceiling after trying to shake it out of your hands and it flies off), and anything else it touches. 
Fantastic stuff as a product, but what a bastard of a thing in every other respect, as it literally NEVER cures. 

[saveasteading]

20 minutes ago, Nickfromwales said:

literally NEVER cures

That is the point surely. When other fillers harden and crack, this stays as a seal.

We used to use a very expensive mastic tape on steel cladding laps.  Doing an extension after 10 years it was still sticky, moving with the building and keeping it air and water tight.

[Furnace]

10 hours ago, IanR said:

I'm not sure I'd call what Touchwood/WilkinsonPH/Adam provides a "kit". Some of the I-Joists do come pre-cut, but many don't. To me it is a stick build, just goes up very fast with minimal waste on site.

Thanks @IanR for that clarification. I appreciate the build time for an MBC-style is faster, but I'm drawn to Adam's offering due to the lack of credit exposure, reduced transportation costs/emissions, plus his undoubted experience in executing.

[Post and beam]

12 hours ago, Nickfromwales said:

I was on site with Adam yesterday. He's Wilkinson Passiv Homes now IIRC.

 

https://wilkinsonpassivhomes.co.uk/

 

 I dont want to stray too far off of the thread here but based on these glowing comments i wondered how far away from me this company operates. You know.... Just in case.   Turns out its less than 10 miles down the road ! who knew. 

[Furnace]

11 hours ago, Iceverge said:

We (me mostly , Mrs and my bro) did this on our masonry build. Zero experience. 0.31 ACH.  DIY blowerdoor really helped too. 

Kudos for that great air tightness result👍

There are undoubtedly many ways to achieve a quality result, but engaged, competent and
motivated workers appears critical almost regardless of build system.
Cheers

[Iceverge]

10 hours ago, Nickfromwales said:

 just employ a 300mm(or more)  twin-wall, a-la MBC ( Larsen?), and kill a few birds with one stone. 

 

Would this not be much more labour intensive in a stick build situation? Also how do you easily over-insulate window + door frames. 

 

10 hours ago, Nickfromwales said:

The electrical and plumbing 1st fix become a ball-ache if the service battens have insulation between them.

 

If you run the service cavity battens horizontally surely it's child's play to run all services? Batt insulation afterwards will fit over pipes and conduit easily I would have thought.

 

10 hours ago, Nickfromwales said:

project will see 50mm timbers tagged onto internal face of the 400mm I-beams to allow for 450mm of Warmcell in the frame; negating any IWI or EWI whatsoever.

 

MEGA U-Value there. <0.9 I would have thought. When you get to those extremes thermal bridging becomes a really significant factor in overall heat loss. What's the tactic re this? 

 

Could you not just pop a few holes for services in the web of a wider I-joist and skip the batten? 

 

 

 

 

 

[Iceverge]

Here's 2 options for my preferred stick build option if I was doing it myself.  Tape the OSB externally as an airtight layer in both cases. Some will complain that this is the wrong side but if I could oversee it then I would be more than happy.\ re the condensation risk.   All off the shelf materials.  The one with external foam could be easily scaled down for thinner walls and lower U values.