Cavity trays above & below sills?

[ruggers]

In a masonry constructed house 100 face brick / 150 partial fill cavity/ 100 dense block and using catnic style lintels. Are trays required below the window sills?

 

Above them a dpc roll can be used with turned up ends into the perps, would this be 450 or 600 roll?

 

The plastic cavity trays for above were going to be really expensive if made to suit, unless people use off the shelf ones?

 

Builder only uses catnic and says above opening trays arent required which ive said im using birtley and 100% want them as its been warranty criteria for decades.

[nod]

Turned up dpc is fine Above window and door openings 

I don’t see how the warranty company can dictate how you build your house 

Tell them to f**k off 

[ruggers]

The warranty company hasn't said anything, I've just went with a local person for it, cheap as they come because its all a paperwork exercise really I'm self building and project managing separate trades.

 

I just wanted to meet the essentials to have a leak free house since using face bricks, but not have to hassle the builder too much who's set in his ways being old.

 

I cant see the benefit of trays under sills if I have proper ones over openings but its worth me asking.

 

Some stone sill on the front, rest upvc. All set back 25mm into cavity.

[nod]

1 hour ago, ruggers said:

The warranty company hasn't said anything, I've just went with a local person for it, cheap as they come because its all a paperwork exercise really I'm self building and project managing separate trades.

 

I just wanted to meet the essentials to have a leak free house since using face bricks, but not have to hassle the builder too much who's set in his ways being old.

 

I cant see the benefit of trays under sills if I have proper ones over openings but its worth me asking.

 

Some stone sill on the front, rest upvc. All set back 25mm into cavity.

My mistake 

Warranty criteria Warranties rarely pay out The type of trays you use won’t make any difference to there cover A sheet of dpc over each opening is more than enough fore 99% of new homes 

 

[ruggers]

What size DPC would you use, 450 or 600? I tired 450 yesterday because i have some, and if fully bedded on the outer leaf, then angled up 225 and horizontally lapped in over the 100mm PIR, it beds in the inner skin by 50-60mm

 

100/150/100

[DannyT]

600mm cavity tray on top of lintel, turned up at both ends, normally at least a brick and a half past the door/window reveal to ensure lintel is covered. Weep vents every 450mm (2 bricks) max.

450mm tray can be a bit of a stretch on 150mm cavity.

Some sites now make us lay a tray below window if it has stone cill with weep vent either end. Not necessary in my opinion.

[ruggers]

Thanks Danny, I've started to install above lintels as you mention, but its sometimes hard to go beyond the width of the lintel due to the Cavity wall PIR & then where the external perps align. 

 

Becuse I'm using the T&G PIR I've been bringing it to each side of the lintel, then cutting it square. And in between the two square edge cuts over the lintel, I've profiled the PIR to the same angle of each lintel leaning outwards, then foil taping the the square edge joints. It helps minimise the cold bridging over the top of each lintel.