Sticking Aerogel to steel

[Beau]

18 hours ago, Great_scot_selfbuild said:

The thermal property of tilebacker boards is nowhere near comparable with aerotherm though.

It's not but you can plaster straight onto it. If you are planning to clad this in plasterboard you could use 20mm XPS and have a thinner overall build up.

[JohnMo]

18 hours ago, Great_scot_selfbuild said:

this aerogel or spacetherm?

Same stuff as in the photo by @Mulberry View. 5 years since I bought it.

 

 

[Mulberry View]

20 hours ago, Great_scot_selfbuild said:

Is this aerogel or spacetherm? From the suppliers I’ve approached, aerogel is like a stiff board/sheet (these pictures look like a loose fabric). It appears that the term ’aerogel’ is used across a variety of products, but not all with the same thermal value.

 

What I bought were Spacetherm A1 pads (I'd call them sheets, but they are pads on the invoice). I had a lot of trouble getting consistent advice on what is what. Proctor are fairly helpful, but they still take for granted that products they work with everyday will make sense to DIY'ers like us!

 

It came in an "8x4" sheet, rolled up. It's reasonably flexible, but they encourage the use of separate pieces on my steel column rather than wrapping it round the corner and I think that was good advice. It would follow a curve for sure, but you wouldn't want to wrap it around 2 sides of an object.

 

FYI, I paid £515 plus VAT for 2 full sheets. The carriage was £40+VAT (included in that £515).

 

I'd post you a small offcut if you want to see it before you fork out?

[SteamyTea]

I think the fibre matrix is made from polyester.

So think of it as a very dusty blanket that has been gathering dirt at your grandmother's for the last 60 years.

Then think about what is sticking to it, and why it does not bend tight to make a good hospital corner.

 

Sleep well in this heat everyone 

[saveasteading]

On 08/07/2026 at 18:51, Nickfromwales said:

Just use XPS tile backer boards

Been reading without comment as I don't know aerogel.

 

But my inclination is  to keep it simple and ensure a good, solid and permanent connection.

What area of steel are we talking about, relative to the wall area? i.e. is it the biggest deal to get maximum insulation?

And what depth is available?

There are several makes, too and its available at my local BM (and yours) , Topps and at Wickes, so about £30/m2 and no transport cost.

 

Depending on detail and access, I'd probably stuff the void of the steel to stop that cavity being cold, and also reducing overall heat loss.

 

[SteamyTea]

16 minutes ago, saveasteading said:

reducing overall heat loss.

Not sure but it may be to do with condensation aliveation. 

[Gus Potter]

On 08/07/2026 at 14:55, Great_scot_selfbuild said:

I am planning to fit a layer of 10mm aerogel to the outside of a steel column. Any recommendations on glue / other methods? (Please state if you’ve managed to do this before - my experience of contact adhesive is that it can behave very differently based on the material type and I’m not sure how well aerogel will take to it.

Ok a bit of food for thought.

 

You have a steel column, likely supporting a structural load. Let's say as a minimum you need some fire protection? Say 30 minutes. 

 

Now you can achieve that in two common ways.

 

1/ Box it in with say Gyproc Fireline board. Which probably gives you a detailing problem, which is why you are probably wanting to use Aerogel as it saves space. 

 

2/ Paint the steel with intumescent paint. But for intumescent paint to work it needs to have space to expand into... you see the dilemma? As a rough rule of thumb the intumescent paint thickness needs to expand some 50 times to work properly. It needs space to do this. So you can't stick Areogell to the steel per say and you need manufacturer approval to stick it to intumescent paint. 

 

Now often BC etc don't pick up on this. But if something goes wrong, there is a fire, the steel fails and the building falls on say the Fire Brigade.. then the buck has to stop somewhere.. as an SE I'll be on the radar, Architect's also, and you if you have taken it upon yourself to become a designer then you are facing a huge liability. 

 

Now the above is a worst case.. but if you get a smart BC officer that knows about this stuff then they might be minded to fail your design unless you can prove otherwise. 

 

There are cases where the steel is well protected by masonry and very heavy and thick and thus possibly as at Paulie

On 08/07/2026 at 16:25, Super_Paulie said:

i used a spray contact adhesive on my internal upright, stuck no problem.

I think in Paulie's case the steels are so heavy they don't need fire protection. The load we use when designing steels for fire protection get reduced as they are called an accidental case. In lay terms we don't design most steels for the building being fully loaded up and a fire starting at the same time. 

 

I would go back and look at what your steels are doing, the loads and so on. Also have a chat with your SE  to check if what you are proposing might invalidate their design for example. 

 

I appreciate you may not like this news.. but it's up to you and your risk. 

[Great_scot_selfbuild]

11 hours ago, Gus Potter said:

the steels are so heavy they don't need fire protection

Not that it applies to us, but my interest is piqued - how 'heavy' for fire protection to not be required?

 

(thanks for the other points - we pored over the fire protection discussions early on in the design stage with the PD, SE and TF company; I've since filled my head with MVHR, UFH.... and need to go back and re-read it all.)

[saveasteading]

It's one of these area over perimeter things. So a chunky steel possibly needs no protection, an certainly less... I've had lots of cases, and knowing the principle can save money and also be easier to build.

(To the extent of using a structurally inefficient steel because of the fire and geometry benefit... this seldom happens in a linear design process. )

 

It's the exposed area, so with a fire on the inner face, only that area counts, divided by the whole cross section.

Thus a column in a wall is less exposed than one in an open area. 

 

The info is provided by manufacturers of protection products. 

 

 

[SteamyTea]

1 hour ago, saveasteading said:

It's the exposed area, so with a fire on the inner face, only that area counts, divided by the whole cross section

Can you explain a bit more.

I assume it is exposed surface area that needs to be reduced or protected.

[saveasteading]

2 hours ago, SteamyTea said:

explain a bit more.

Without referring to documents..

It takes a huge temperature rise for steel to soften and fail.

If it was all exposed to fire the heat would rise more quickly than if some is protected.

A skinny section of steel conducts the heat more quickly.

So a typical example of partial protection is being partly enclosed by a wall or having a concrete plank floor sitting on it.

 

The steel is not being protected in the long term. Continued heat will make it fail. But it is being designed to remain structural for a period of time.

 

Thus we could find that an exposed light column needs lots of intumescent paint while a heavy section needs nothing or a thinner coat.

 

I've dealt with 3 fire damaged steel buildings. An agricultural one was a write-off.

One we had built a few years earlier  only needed cleaning and painting.

The third was within an external fire wall (steel cladding  and fibreglass insulaion) ..  no damage other than to the paint on cladding and column   (fire officer amazed).(the fibreglass was converted back to  sand).

 

I don't know if that's a complete or logical answer, so keep asking.

[Nickfromwales]

1 hour ago, saveasteading said:

Without referring to documents..

It takes a huge temperature rise for steel to soften and fail.

If it was all exposed to fire the heat would rise more quickly than if some is protected.

A skinny section of steel conducts the heat more quickly.

So a typical example of partial protection is being partly enclosed by a wall or having a concrete plank floor sitting on it.

 

The steel is not being protected in the long term. Continued heat will make it fail. But it is being designed to remain structural for a period of time.

 

Thus we could find that an exposed light column needs lots of intumescent paint while a heavy section needs nothing or a thinner coat.

 

I've dealt with 3 fire damaged steel buildings. An agricultural one was a write-off.

One we had built a few years earlier  only needed cleaning and painting.

The third was within an external fire wall (steel cladding  and fibreglass insulaion) ..  no damage other than to the paint on cladding and column   (fire officer amazed).(the fibreglass was converted back to  sand).

 

I don't know if that's a complete or logical answer, so keep asking.

For a box section of equal dimension, this I assume would be difficult for heat to affect easily, but I beams (UB & UC) with different thickness materials making the one profile, thus reacting differently over time / temp, the focus would be more on those?

 

However, the ‘system’ would just blanket the solution for worst case, methinks, vs giving chapter and verse for each different scenario.

 

Just my uneducated guess…..

[SteamyTea]

Until the yield point is reached, it is really just differential thermal expansion (in a fire situation) that causes the buckling point to me lower. So what may be fine at 50°C, may have problems at 75°C even though it is well below the critical temperatures of the material, due to the change is sizes (expansion) in 3 dimensions.

This can be made worse if 2 of the 3 dimensions are fixed in place.

Think of a beam that is rigidly fixed at each end and has a weighty slab on it. When it heats up, there is only two degrees of freedom, one downwards and the other sideways.

A bad design would not take those small movements into account, a good design would, and know which way it would ultimately fail.

Another way to think of it is removing a few bricks from the base of a tall chimney. Each individual brick does not carry much load, so removing it cannot do any harm!

[saveasteading]

3 hours ago, SteamyTea said:

only two degrees of freedom, one downwards and the other sideways.

That's another issue than the fire protection, but a chunky beam that is inefficient in normal use can then use that extra stiffness. 

Next time you're in a big warehouse , reasonably modern, if you look up at the rafters, they are likely to have diagonal struts. They're not for fire but show how stiffness can be provided.

Likewise if a floor is built in line with a beam, or a wall into a column  it won't distort.