Timber frame cavity wall

[Grsz]

Hi!

 

I’m learning architectural terms/methods because it interests me a lot. Sorry if some questions are stupid, I’m a newbie in this.

 

There seem to be many different types of foundations, slab layers, insulation, and wall types.

 

The most common I’m reading about is cavity wall where there insulating material is sandwiched between two shells of walls. I’ve been reading around and where things get very blurry is block, and timber frame.

 

Some places mention internal shell being timber frame, outer brick work, where some places mention bricks only as cladding, not bearing load.

 

Some mention different cladding can be used for a timber frame, where the insulation material is between the posts, but based on my limited understanding, it’s not a cavity wall anymore?

 

And the third case where the inner skin is block, the outer being brick, and timber in the gap, filled with insulating material (which is the most confusing).

 

Some also mention the gap filled, some unfilled.

 

I read detail drawings, forums, asked chatgpt, the more I read, the more confused I get.

 

Can someone shed some light to clarify the above?

[SteamyTea]

I think you are into a case "ask 100 engineers and you get 100 right answers".

 

What you need to do, initially, is break it down into important parts i.e. structural forces, thermal properties, looks, easy of construction, price etc.

Then analysis each part and how they go together.

 

Some construction methods have developed over millennia and it is only in the last 250 years that post rationalisation has happened.  An example of this is one of my favourite discussions about lime versus Portland Cements.  They are both interesting and do their jobs well, but many think that the traditional lime mixes are better 'because the Romans used them' (even though the Egyptians beat them to it by a 1000 years at least).

Another example is, as you have found out, is to do with cavities.  These are a relatively late development and were originally just a rain screen over a solid structural wall.  Trial and error, plus improvements in materials and manufacturing processes, the simple wall has changed to a two walls, tied together, with some being single load bearing, other both load bearing, and sometimes filled with insulation.  The designs are used differently for different purposes, sometimes it is just decorative, other times it is structurally important.

 

Another area you will soon find out about is the thermal performance, again, there are many different opinions.

Some say that you need the insulation on the inside, other say on the outside, this is because while mathematically the U-Value of a wall is the same in both directions, the energy inputs may not be i.e. a heated house may be putting 5W.m^-2 though a wall at night, but when hit by bright sunlight it may go to 100 W.m^-2.  Totally different regimes for the same structure.

Then there is air and water tightness.  Traditional masonry walls are inherently 'leaky', so putting insulation in a cavity may cause thermal bypass problems or the insulation type may absorb water.  This is why internal insulation (on the room side of both cavities) can give a better performance than the same amount of insulation value within the cavity.  The same may be true for external insulation, but could be harder to fit because of roof overhangs and window reveals, but is often easier to install because there are no joists or wires to move (this is more about retro fitting than new builds)

 

So basically, it is hard say if there is a best system, it is a case of 'it depends'.

All systems can work well if designed right, just as all systems can fail if executed badly (by twat builders).

 

The main things to keep in mind are:

Will it be strong enough

Will it keep the weather out

Will it look right

Will it last

Is it affordable (the space station is strong, thermally brilliant and air tight)

Can it be repaired and modified

 

That is enough to be going on with I think.

[stu w]

1 hour ago, Grsz said:

Hi!

 

I’m learning architectural terms/methods because it interests me a lot. Sorry if some questions are stupid, I’m a newbie in this.

 

There seem to be many different types of foundations, slab layers, insulation, and wall types.

 

The most common I’m reading about is cavity wall where there insulating material is sandwiched between two shells of walls. I’ve been reading around and where things get very blurry is block, and timber frame.

 

Some places mention internal shell being timber frame, outer brick work, where some places mention bricks only as cladding, not bearing load.

 

Some mention different cladding can be used for a timber frame, where the insulation material is between the posts, but based on my limited understanding, it’s not a cavity wall anymore?

 

And the third case where the inner skin is block, the outer being brick, and timber in the gap, filled with insulating material (which is the most confusing).

 

Some also mention the gap filled, some unfilled.

 

I read detail drawings, forums, asked chatgpt, the more I read, the more confused I get.

 

Can someone shed some light to clarify the above?

The majority of timber frame in the UK is filled between the timbers with insulation whether it be PIR or Mineral slab type and alot are full fill, then extra insulation can be added to the structure inside or out to meets u values, again depending on construction.

A vast selection of  Modern Breather membranes and vapour barriers are then used to control moisture inside and out.

The timber frame can then be clad in a variety of ways depending on the outside construction. 

Brick slips,  cement board ,render, pvc,wood etc can all be used as cladding with a cavity incorporated on the outside to cobtrol moisture and condensation.

A cavity can also being created and have a conventional brick skin on the outside which is tied into the timber frame

Sips panels can also be used which is usually 2 sheets of osb with insulation injected inbetween the board to make a self contained panel , again can be finished on the outside as above depending on the end use/spec 

Have a look on websites like Fleming homes, mbc , etc timber frame companies and it will be more clear than my brief description 

 

Edited April 14 by stu w