Drop lintels- how

fclauson

Quick bit of advice please

If you want to achieve a drop lintels at head of window for the outter leaf for a 250mm wide cav build out what methods do people recommend - do you have a special lintel with a step in it - or do you do something clever with the block courseing.

mickdw

What exactly are you trying to achieve?

fclauson

ok - sorry for lack of clarity

The head has a split lintel - the outer lintel is specified as being 20mm below the inner one (as are the sides 20mm narrow outter leaf to the inner leaf)

This is to give a robust window detail for weather etc

DOCARCH

Most or many of the main insulated steel lintel suppliers will do a stepped lintel with 20mm drop to the outer leaf.

sinnerboy

fc - simply saw cut 20mm from the blocks that the outer leaf lintol sits on. Then thick joints over lintol to recover coursing is the bog-simple way - assuming you are applying a render coat over to conceal this ugly method.

For a neat look omit the support blocks and construct cast in situ lintols to the shape you need i.e. on elevation the lintol has "boots" to both ends.

beyondpassive

This type of thing:

sydthebeat

BP, whats the steel angle at he head for?

sinnerboy

+1

looks like a condensation run off trap
also I would prefer to see the DPC step up another block course to the inner leaf.

beyondpassive

Its just a glavanised channel to keep the cavity closer in place.
Agree Sinnerboy, cavit tray should be higher, but then that little toblerone can be hard to fill on long and corner windows. All comments and suggestions on this detail much appreciated, its an evolution of the ply box cavity closer detail.

sinnerboy

beyondpassive wrote: »

Its just a glavanised channel to keep the cavity closer in place.

The vertical leg should turn down so that it does not trap condensation run off from the inner face of the outer leaf. Anchor it the the outer leaf lintol thus pinning the dpc tray in place here before you offer it up.

sydthebeat

from a buildability point of view, i think fixing that channel would be quite difficult.

Couldnt a simple friction fitted piece of 50mm PU board do the same job here?
It also creates the junction between the DPC and outleaf. If using a channel your puncturing it every time the closer is fixed.

Thats our stanard spec around 150 cavity pumped these days.

beyondpassive

sydthebeat wrote: »

from a buildability point of view, i think fixing that channel would be quite difficult.

Couldnt a simple friction fitted piece of 50mm PU board do the same job here?
It also creates the junction between the DPC and outleaf. If using a channel your puncturing it every time the closer is fixed.

Thats our stanard spec around 150 cavity pumped these days.

I'll check that out on site. I'll say to the forman 'Its just crazy enough to work' :-)