Construction Method Philosophy (selecting TF vs Mason vs ICF)

[puntloos]

One frustrating thing about selecting build methods is that you can find glowing proponents for pretty much everything, and those proponents seem to wave away all concerns with something like "oh, but if you do it properly then it'll be fine!"

 

TF has worse sound insulation.. but if you do it properly..

Brick is harder to get airtight.. but if you do it properly..

Passivhaus tends to overheat in big summers.. but if you design it properly....

 

Instead what I'd like to know: (I'm listing some examples/myths? I've picked up, but please correct me.... without saying the word 'properly' .. )

 

- Are there any unique-to-timberframe problems that one simply would not have with masonry

• Changing your mind about the 'shape' of your house is near-impossible once you've put in the order. 
• Rotting beams after being exposed to water
• Flimsy walls can't carry weight (such as a large mirror) unless pre-planned.
• Sound carrying (footsteps, toilets flushing, home cinema) much further
• Are there any examples of major design flaws with TF that meant some? all? of the produced frame had to be discarded and do production again with a fixed design?

 

- Are there any unique-to-masonry problems that are actually solved by TF?

• Brickies are human, so various precision-related issues, large items that do not fit, harder to get airtight, etc
• Long time before watertight, so risk of water causing hassle
• Load bearing walls very hard to modify, don't try to open an unwanted wall, TF is probably fine to remove a wall here or there

 

- Are there any general principles that can be said about these choices?

• Is building in TF more, or less risky than building traditional?
• Is building TF 
• People tend to say 'tried and true' but clearly with almost "3D printed" timberframe, as long as your design is good (big if? maybe?) then the TF will max that to the milimeter?

 

and finally:

- Is ICF meaningfully different from TF in these considerations?
- How do I get proper specialists to do it properly in the first place, and/or how do I force them to do it properly.

[PeterW]

2 minutes ago, puntloos said:

How do I get proper specialists to do it properly in the first place, and/or how do I force them to do it properly.

Don’t get into a race to the bottom line...! Simple as that..! Cost / Time / Quality - pick 2...

 

You want quick with quality then it will cost more. If you want quality then you need to spend time on site and set expectations. Talking to the trades - make them a brew, buy some bacon butties - will get you more information than shouting at them when they haven’t understood the detail in a 50 page plan set. 

 

Want to set performance criteria for trades using contracts ..? Then that will cost you twice, as you’ll need to write the spec and also expect trades to add a premium to their prices to cover potential issues. 
 

On your list I’m not sure where it has come from as some of your TF issues can be apparent in any build method such as sound transfer. Most modern masonry (brick and block) also has a lot of timber framing within it such as stud walls.

 

In reality there is no perfect build system but if you actually invest your own time in the build then you will get a much better result. 

[puntloos]

2 hours ago, PeterW said:

On your list I’m not sure where it has come from as some of your TF issues

Other than sound (below), which other ones?

2 hours ago, PeterW said:

can be apparent in any build method such as sound transfer. Most modern masonry (brick and block) also has a lot of timber framing within it such as stud walls.

@jack mentioned it, but more in general, as before, "if done properly" things can be avoided and "if done not properly masonry can also have trouble". 

I'd just note that as a simple principle, if a building has more physical weight, it's harder to move it around with soundwaves ?

 

2 hours ago, PeterW said:

In reality there is no perfect build system but if you actually invest your own time in the build then you will get a much better result. 

 

.. or pay someone to invest theirs? ? But yes, true.

[nod]

If you are looking at cost 

Traditional will cost you far less than TF 

[PeterW]

5 hours ago, puntloos said:

 

I'd just note that as a simple principle, if a building has more physical weight, it's harder to move it around with soundwaves

TF and masonry share a similar construction method when it comes to internal walls - stud work. The mass is in the external walls, all internal walls and floors / ceilings are the same so issues can and will occur. 
 

Which “TF” method are you referring to anyway..? There are loads ! And not all are inherently air tight, most of the new build properties around me have a TF inner frame and are barely hitting decent BRegs air test results. 
 

TF shrinks - which gives issues for outer skins that don’t such as brickwork and allowances have to be made. 
 

TF can dry and crack plaster finishes if it twists as it dries. Masonry can do the same but in different ways. 
 

It used to be said that insulation was better in TF as it was added when the building was watertight - masonry can be the same as you can use blown beads. 
 

The list goes on - for each “system” there are a list of pro’s and cons and it comes down to personal choice. 
 

5 hours ago, puntloos said:

 

.. or pay someone to invest theirs? ? But yes, true.

But that moves you further and further away from self build to custom build. And the bills can still mount up. Have a look at the series following John Caldwell and his “million pound mansion” in Mayfair ... started with a £10m budget and spent £60m .... 
 

 

 

[Oz07]

Everything is fine if done proper. One unique problem I can think of is sole plate condensation. You will have to get a risk thingy done to make sure the risk is low. 

Also with regards to membranes and water or condensation ingress. It could be a major structural problem with tf. Less so with masonry. 

[SteamyTea]

Seems to me that any method can fail.

I had a Victorian brick house, noise transmission was dreadful, save with my Portland Stone and Cob place.

I also had a Lightweight Block and Brick place, good insulation, very little sound transmission, but all the plaster was cracking, except on the timber stud wall.

Now got a timber frame place, noise transmission is pretty good, but as it is terraced, when a neighbour slams an external door (they have moved on thankfully), all 4 of the houses shake.  I think this is to do with the airtightness.

Now for things going right, and an analogy.  If I go and buy a tin of Heinz beans, I know exactly what I am getting.  But I can over cook them to a mush, or microwave them so only the top layer is cooked (microwaves don't really cook from the inside).  So a Timber Frame is nearly always going to leave the factory as good as it can be, it then gets corrupted on site.

Bricks are generally made to a good size tolerance, and a good bricklayer will put them in the right place.

Design is very important though.  A house can be built out of just about any solid material, just that they will have different limitations.  Try and cheat those limitations and you get problems, work with them and life will be good.

Insulation is a difficult one as it must be designed with airtightness in mind.  This is why sheet insulation is so good, follow the instructions and you get airtighness as well.  wool insulations need to be isolated from external air movement, so an outer leaf will been to be made airtight, after that, moving inwards, it matters not a jot, the warm air is trapped.

ICF, on the face of it, seems to 'cure' all these problems, but it does require very good onsite skill levels (like a brick built place).  But it seems to cause a a lot of people problems, but that may be because they lack experience.  I don't see many ICF housing estates, but I see a lot of factory built TF ones.

This "Time, Quality, Cost" pick any two, is wrong, go can have all three, just looked to the automotive industry and see what you can buy for £15,000.

[Ian]

@puntloos

It's an interesting question, and one that I gave some thought before building my last house using timber frame.

 

My normal preference would be for brick and block traditional construction however the site I was building on was in a remote part of N Wales that lent itself to timber frame construction. It was very difficult to access up a steep single-track and partially unmade road, the site is on an exposed hillside and has a short construction weather window with snow & ice making access impossible for good chunks of the year. The ground has clay in it and it turns claggy in the heavy rain of that part of N Wales which can make the movement of heavy building materials difficult.

 

I chose a local timber frame manufacturer who was used to dealing with the difficult access and weather conditions. They pre-fabricated the frame in sections that were suited to the site conditions. We agreed that they would start work on site in late Spring and they got the build weather-tight after just 2 weeks on site.

 

I'm very happy with it and 4 years on I still think I made the right choice of construction method for that particular site.

 

The potential disadvantages of timber frame in my view are that timber can rot which makes the construction detailing more important than for a masonry build. I'm an architect and  designed the house with traditional pitched roofs to an uncomplicated design with outboard gutters. The biggest risk with timber frame construction is if you get water leaks into the structure from either poor basic design or construction detailing. EG: there's a fashion amongst some architects for putting the gutters inboard of the external wall which I've always thought was a crazy idea and asking for trouble - the kind of thing in the photo below. It's done to make the building look better but seems like a bizarre thing to do when we all know how often gutters get blocked and overflow.

 

If you're into horror stories and want to read about what can happen if you get the design & construction detailing wrong with timber frame construction then have a read about the 'leaky condo crisis' in Canada & NW USA. 

https://en.wikipedia.org/wiki/Leaky_condo_crisis

 

 

Edited November 24, 2020 by Ian

[SteamyTea]

12 minutes ago, Ian said:

If you're into horror stories and want to read about what can happen if you get the design & construction detailing wrong with timber frame construction then have a read about the 'leaky condo crisis' in Canada & NW USA. 

Or go back to Barratt Homes in the late 1980s.

 

It is sometimes hard to disaggregate and isolate the real causes of failures, it could be choice of materials, design failure, construction detail.

[joe90]

I have gone from straw bales build through timber frame to ending up with brick and block. The reasoning behind it was I like the look of brick, requires no maintenance and suited our cottage look. I also like “heavy weight “ internal walls (block) so I can hang anything without future planning. “Heavy” (used to be called thermal mass) can help with regulating temp fluctuations and it really works with our build. Brick and block can be airtight if done correctly with an eye to detail. We were lucky that we found a very good local builder who took on board our “passive” principles and engaged very well with them and us (but I was on site all the time). Horses fir courses.

[SteamyTea]

5 minutes ago, joe90 said:

“Heavy” (used to be called thermal mass) can help with regulating temp fluctuations

Or not.

[joe90]

2 minutes ago, SteamyTea said:

Or not.

well, my new build constantly sits between 20 and 21’ and varies very little. Heating yet to come on this year, wood stove lit a couple of nights (more because of “feeling “cold and dark with oncoming winter, but temp still 20’ when it was lit). I am sure others can achieve this as well (TF with blown cellulose springs to mind (( Jeremy’s)) but his overheated).

[SteamyTea]

51 minutes ago, joe90 said:

but his overheated

That was a design flaw, not the materials.

 

I think this is part of the problem, we don't spend much on designing houses.  We spend a lot on styling them, but that is only part of the process.

Passivhaus at least tries to make a stab at it, and the software (well spreadsheet) is probably pretty good.  Then someone comes along and sticks a window in the wrong place, and then, refuses to do anything to mitigate the problem, and then tells everyone 'Passivehaus is rubbish, it overheats".

[joe90]

7 minutes ago, SteamyTea said:

That was a design flaw, not the materials.

Oh I agree, he had a microclimate that was not part of the modelling, I was very impressed with his materials (apart from the wood cladding, but that was a planning stipulation). I was told my South facing large conservatory would overheat horribly but that’s not been the case, again location mitigated that to a large degree.