curlewhouse Posted May 4, 2017 Share Posted May 4, 2017 (edited) So looking at the plans and I'm supposed to buy insulated catnics - but looking at them the insulation makes no sense as they are one giant cold bridge. The amount of heat transfer through the air in their cavity would be so minor compared to that whacking great bridge of metal that I'm not clear if it is simply an attempt at blagging. Am I missing something? Edited May 4, 2017 by curlewhouse Link to comment Share on other sites More sharing options...
PeterW Posted May 4, 2017 Share Posted May 4, 2017 I don't think you can buy uninsulated lintels now ..! Yes it is a cold bridge but unless you want the joy of building two separate skins and managing the lintels and the insulation and openings they are no worse than the big expanse of glass below the lintel..! Link to comment Share on other sites More sharing options...
Declan52 Posted May 4, 2017 Share Posted May 4, 2017 You can use a single skin lintel on the outside for the bricks and a concrete head on the inside. Then bring whatever you have in the cavity down to fill the gap. 1 Link to comment Share on other sites More sharing options...
DNA Posted May 4, 2017 Share Posted May 4, 2017 Hi Declan52. I never thought of that. Has anyone done any cost comparisions between cavity lintels and the option of using an external galv lintel and a concrete internal one? Link to comment Share on other sites More sharing options...
PeterW Posted May 4, 2017 Share Posted May 4, 2017 Concrete internal lintels start to get expensive and unwieldy at anything above 1700mm as they are invariably 215 x 100mm and that gives 27kn loading. As an example using 1800mm lintels Catnic single (£32) Naylor Concrete (£69) £101 catnic CG90 £43 It does make sense if you go over a 200mm cavity as the pricing goes silly for cavity lintels at anything above 125mm Link to comment Share on other sites More sharing options...
DNA Posted May 4, 2017 Share Posted May 4, 2017 Good point Peter. There was an outside chance there of my lintel schedule cost dropping a bit! Link to comment Share on other sites More sharing options...
Declan52 Posted May 4, 2017 Share Posted May 4, 2017 (edited) 20 minutes ago, PeterW said: Concrete internal lintels start to get expensive and unwieldy at anything above 1700mm as they are invariably 215 x 100mm and that gives 27kn loading. As an example using 1800mm lintels Catnic single (£32) Naylor Concrete (£69) £101 catnic CG90 £43 It does make sense if you go over a 200mm cavity as the pricing goes silly for cavity lintels at anything above 125mm Wouldn't need a 9 inch head for that span, 6inch would be fine. I have 2 concrete prestressed heads at 4.4m long over my patio doors. They took some handling!!! 2 Brickies will easily lift heads up to 2.5m and if they are bigger you can always use a digger or telehandler to sling them in. Edited May 4, 2017 by Declan52 Link to comment Share on other sites More sharing options...
PeterW Posted May 4, 2017 Share Posted May 4, 2017 Even a 6" head is £43 so pricewise you are more than double. Difference is you can pick an 1800 catnic up with one hand ..! Link to comment Share on other sites More sharing options...
Oz07 Posted May 5, 2017 Share Posted May 5, 2017 I got 150mm cavity lintels cheap enough. There not so unusual now Link to comment Share on other sites More sharing options...
PeterW Posted May 5, 2017 Share Posted May 5, 2017 My 150s came direct from Catnic so on a 4 day turnaround - most BMs have 100s on same day in stock which isn't a huge delay but you need to bear it in mind. I used Condell online and they beat everyone's prices Link to comment Share on other sites More sharing options...
Mr Punter Posted May 5, 2017 Share Posted May 5, 2017 I tried to spec the Keystone Hi Therm lintels, which have a thermal break and a much better Psi value. Lead times made them impractical though. Link to comment Share on other sites More sharing options...
Lin Posted January 28, 2018 Share Posted January 28, 2018 (edited) We are converting a building that has catnic lintel already in situ over a wide opening that will become bifold doors The lintel is uninsulated. Is there much point trying to squirt insulating foam through the holes (there is a regular pattern of holes on inner side of the lintel) to try to fill it up the hollow with an insulator ?? Thanks Edited January 28, 2018 by Lin Link to comment Share on other sites More sharing options...
Nickfromwales Posted January 28, 2018 Share Posted January 28, 2018 Yes, plenty of merit to that solution. Just be sure not to allow the foam to expand beyond the end of the lintel. 1 Link to comment Share on other sites More sharing options...
PeterW Posted January 28, 2018 Share Posted January 28, 2018 2 hours ago, Nickfromwales said: Yes, plenty of merit to that solution. Just be sure not to allow the foam to expand beyond the end of the lintel. +1 to that. Squirt the inside with a bit of water at each end to make it go off quicker and then fill the last 6" of each side. Let it go off for a few hours then go back and fill the centre section up through all the holes. Strangely satisfying, but don't stand under it once you've done it as you will get it in your hair... ask me how I know ! 1 Link to comment Share on other sites More sharing options...
MikeGrahamT21 Posted January 31, 2018 Share Posted January 31, 2018 Check IG lintels out too, even their standard lintels have a much lower PSI value than catnic if I remember right, and they're cheaper! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now