Airbricks

[victorianjob]

I'm in the process of restoring an old Victorian Mill owners house. House currently has a mismatch of corroded cast iron airbricks and modern type terrecotta replacements. I'm thinking to replace with cast but I'm having difficuly deciding what colour to paint them. Is the idea for them to be a feature or to 'blend in?' House is red brick with very little stone detailing, guttering and downspouts will be black, is it right to match with guttering colour?

Thanks for any help!

 

[Gareth Hughes]

I'm pretty sure that "same colour as other metalwork" would be the correct course. Just bumping this one up for others' comments (new users' posts can disappear to the bottom of the page very quickly, but welcome!).

 

[Flyfisher]

Welcome to the forum.

I'd say that the house will benefit so much from having the modern terracotta airbricks replaced with cast iron ones in the original style, that you could be forgiven for painting them whatever colour you personally prefer (well, within reason :wink: ).

Personally, I'd paint them black.

 

[Lime]

Buy older second hand ones that are galvanised.
They don't need painting and blend in quite well.

 

[88v8]

Another vote for black. Best painted before they're mortared in, less inclined to rust.

Ivor

 

[victorianjob]

Thanks for the suggestions. I've managed to find a cast iron brick that looks similar to what's left of the originals. I tried to find reclaimed but for less than half of what I need (I need 7 double and 15 singles!) it was well over budget. Thanks for the tip on painting first. If I can get them delivered for tmrw that is this w/ends project!

Thanks!

 

[Feltwell]

Where are you getting them from? Prices can vary a lot, do shop around.

Longbottom's are (relatively speaking!) cheap and very helpful for rainwater goods, and they do airbricks - no proper website as such, you'll have to ring them for a catalogue.

http://www.longbottomfoundry.co.uk/

There's also this chap who has posted on here in the past:-

http://www.castironairbricks.co.uk/

And I'd paint them to match whatever colour you do your rainwater goods - black or dark green personally - or of course whatever colour you happen to like, it's your house!

 

[DJH]

I've made them in hard (antimonial) lead in another life. We used to call them Quarries for some reason and they didn't need painting as the final silver grey patina looked good.

Doug

 

[castiron]

Interesting point regarding painting air bricks.

We often have customers prefer to have them painted, which is great for business as we charge extra for painted air bricks over bare metal. They are worth the extra tenner for painting as we use three pack epoxy primer in grey which we spray front and back and then allow to cure before using a two part epoxy black gloss top coat painted back and then front. The paint is seriously good stuff, Selatex german Paint which is suitable for application to metal (actually for cars) it's the only foreign product we use and sell out of our entire range, all the goods are British.
The air bricks then have to pass the visual test from the front so quite often one coat of black is not enough - that's because cast iron is quite absorbant and even with the primer on it can still take a couple of coats to get the finish looking even. It sounds quite a lot of work - and believe me it is, but don't forget we paint around 30 at a time so over the 3 days it takes to get them finished it's worth doing, both financially and of course pratically. We've had our test air bricks out on the hillside here on Exmoor for 3 years now and they haven't started to rust yet.

Anyway, the reason I've gone into so much detail about painting the air bricks is to illustrate the preperation necessary to get a good finish and also to point out a key point. We spray the air bricks - not hand paint them. Thats because cast iron air bricks are made from iron and therefore you can assume that oxidation is already underway the moment you paint them so you need to get a good key of primer on and keep it as thin as possible. Same goes for the top coat - keep the layers thin. Don't slap loads of paint on them as you'll narrow the vent holes. You'll need to start with an air brick that's as rust free as possible, otherwise you'll trap in the rust and after a year the paint will start to flake off. Of course our bare metal air bricks are stored in a heated warehouse straight from the foundry to keep them as near as possible to rust free before we prime or sell them. When they are sent out in their bare metal state they look like they wouldn't rust - but the moment they get wet, they'll go rusty.

OK - so you'd think I'm trying to sell you the idea that you need to paint the air bricks and you need to get us to spray paint your air bricks as it's not something you would be able to do at home, right? After all, we're making an extra tenner on the painted ones? Well no, nothing could be further from the truth.
We are forever trying to persuade customers with brick properties, if they have a choice to choose bare metal air bricks
After all, the Victorians and Georgians didn't paint them, they left them to rust and eventually they would go un-noticed as the colour merged with the brickwork. Whilst they rust, the coating of rust protects the iron inside and prevents further corrosion - it should last 100 years or so. No paint required. No regular maintenance except for keeping the vent holes clear from any debris every 5 years or so.

I have said "Brick Properties" should have bare metal and please note that. If your property is stone or rendered or painted then you would seriously need to consider painted air bricks as the rust is likely to bleed down onto the stonework or render.
We would generally recommend painted air bricks and vents for these properties.

Please note we only paint our vents and air bricks black but we have supplied them primed so customers can spray them at home (using spray cans). We have also double primed them, so customers can have them in grey - which works really well. I wouldn't recommend galvanised air bricks or vents (we don't sell these because the galvanising tends to reduce the vent holes too much and they don't look very nice) and I doubt if they would be appropriate for listed properties.

Adrian Budd
Cast Iron Air Brick Company

 

[88v8]

Interesting point regarding painting air bricks.

...you can assume that oxidation is already underway the moment you paint them so you need to get a good key of primer on and keep it as thin as possible

Thankyou for taking the trouble to go into so much detail, and no I don't care that its might be construed an Infomercial....

What you say about corrosion is also true of steel, of course, and is the reason why some car restorations fail after relatively little time - bodywork sanded to bare metal and left before priming so that there is, in effect, rust already starting underneath the paint.

If I really want to ensure no rust, after stripping or on bare metal I apply Jenolite or an equivalent acetic acid product before priming. I painted some cast vents I installed in our previous house in the early 80s, and after 25+ years some, but not all, were just starting to show rust around the edges.

One can also paint galvanise, of course, with an appropriate primer, but I accept what you say about the galvanise reducing the vent area.

Ivor

 

[castiron]

Hello Ivor,
that sounds as if you have a good paint system in place.
We have some cellar vents that are galvanised and we paint them, with the same paint top coat as I mentioned previously.
We do however use a different primer, we use an etching primer which i belive is acid based - perhaps similar to the rust preserver you mentioned.
regards Adrian