treatment of existing leaking / cold lintel

[Moonshine]

I have an existing issue with a lintel, that if it's really windy and rainy we get a leak above a patio door of a cavity brick wall.

 

It's an old construction as it's two steels rather a joint lintel. 

 

It looks like the outside steel, has a timber below, which is externally rendered. During construction it looks like a hole was cut in it (attached image) to make a cross member to allow a board to be fixed to it. It's through here that it looks like cold air and water are getting.

 

The question is how to treat it to make as water tight and resistant to cold as possible?

 

My initial thoughs are to seal the hole in the timber with a load of silicone sealant, fill the cavity between the steels and above with 100mm porous insulation, then put a section of pir board across the cavity at the timber level below the steel, and put a piece of ply under the pir.

 

Edited November 2, 2019 by Moonshine

[Mr Punter]

I may have this wrong but could it be lack of any cavity tray and weep holes above the lintel?  This would normally be a DPC sloping down from the inner leaf and built into the brickwork above the lintel.

[Moonshine]

Umm, it may not be that small hole.

 

There is clear water marks running down the exterior wall leaf lintel, and the bricks above the exterior lintel are wet, internal are dry. There is a rigid cavity tray above the lintel that looks o.k.

 

It seems like there is something more going on than just that small hole in the timber.

 

The exterior render above the patio door looks o.k with nothing blown or holes, Though there are areas of moss.

[Moonshine]

2 minutes ago, Mr Punter said:

I may have this wrong but could it be lack of any cavity tray and weep holes above the lintel?  This would normally be a DPC sloping down from the inner leaf and built into the brickwork above the lintel.

 

There is a concave cavity tray above the lintel but no weep holes seen externally.

 

The house has had blown insulation in the cavity and I presume in/above that cavity tray is soaking wet insulation, could that be transmitting the water to the exterior brick and then run down?

 

The leak issue only happens on very od occasions of very wet weather.

 

[Mr Punter]

The water could be getting in anywhere on the wall.  The bigger the wall and the more exposed the worse it will be.  It may be worth doing a close inspection next spring, when the weather is better.  Check for cracks and hollow areas.

[Moonshine]

19 minutes ago, Mr Punter said:

The water could be getting in anywhere on the wall.  The bigger the wall and the more exposed the worse it will be.  It may be worth doing a close inspection next spring, when the weather is better.  Check for cracks and hollow areas.

 

Yeah it's the most exposed wall of the house, especially with the weather at the moment.

 

What do you think of the plan to close it up?

[Mr Punter]

Wait until spring.  If you fill any cracks in the render, then insulate the lintel void you should be OK.

[Russell griffiths]

I wouldn’t fill anything before you work out the water problem 

is there another window above that one. 

 

Any moisture in the cavity needs shedding to the outside before you lock  it in. 

You could stuff a towel up there to stop the draft while you work out the bigger problem. 

 

Edited November 2, 2019 by Russell griffiths

[Moonshine]

1 hour ago, Russell griffiths said:

I wouldn’t fill anything before you work out the water problem 

is there another window above that one. 

 

Not directly above, thought one slightly off to the side.

 

It's odd as I can't imagine it getting through the cavity tray above as I would have thought it would be tied into the leaves.

 

From the looks of it, it could have been going on for a while, but only evident after periods (e.g. days) of prolonged rain.

[Moonshine]

looking at it some more, I think that it is an issue of wind driven rain, as it is on the wall with the greatest exposure to the elements.

 

The rain has got into a crack in the render (just visible in the attached images) and an area where the patio door frame isn't sealed properly to the render.

[Russell griffiths]

You need a series of weep holes above the cavity tray to eject the water

[Cpd]

I am wondering about that moss, is this because water is building up inside and leaching out and this provides the moss with adequate moisture to grow in that specific low down spot ? I would agree that I think the problem is water getting in above and solving this should be a starting point. 

[Moonshine]

Looked at the wall in a bit more detail and it looks like the render in parts has blown and cracked on places allowing the water ingress. 

Looks like a job for the spring!

[Moonshine]

On 02/11/2019 at 16:58, Russell griffiths said:

I wouldn’t fill anything before you work out the water problem 

is there another window above that one.

 

 

I think the cause of the problem has been found, water getting in below roof tiles and down the cavity.

Found thanks to this photo

 

Note the dis-coloured render to the left and right of the facade, directly under the pitched roofs, but not under the half hitch section.

 

It looks like when it's windy rain in blown under the tiles.

 

The solution could be repoint under the tiles, and put a pvc white sheet to cover the side of the tiles, which has a small lip to go over the tiles a bit

[Simplysimon]

stick a dry verge on it

[Moonshine]

8 hours ago, Simplysimon said:

stick a dry verge on it

 

Exactly where my reaserch led me to last night, looks like I fix a 25mm batten to the current verge, and screw the dry verge onto that.