Lintel bearing for 900 opening

[Loz]

Hi,

 

Confused myself on regs (we are in Wales) for lintel overhang (bit that rests on block work), always thought was 150mm each end on new block work, builder put some lintels in today over a 900 wide window opening, the window is on first floor with a second floor to go above.  The overhang is approx 130mm each end - googled it and found in couple of places saying can be reduced t0 100mm on openings less than 1.2m - is that correct as also saw some posts that that changed a few years back to always be 150mm ?

 

Any clarification much appreciated,

 

Lawrence

[Temp]

NHBC say..

 

https://nhbc-standards.co.uk/6-superstructure-excluding-roofs/6-1-external-masonry-walls/6-1-12-lintels/

 

Lintels should extend beyond the opening (at each end) by the minimum lengths shown in Table 5.

Table 5: Lintel bearing

	Minimum bearing length (mm)
Span (m)	Simple lintel	Lintel combined with cavity tray
Up to 1.2	100	150
Over 1.2	150	150

 

 

Elsewhere it says the lintel manufacturers recommendations must also be followed if they require more than 100mm.

[Temp]

From Welsh Approved Document A page 31..

 

https://gov.wales/building-regulations-guidance-part-structural-safety

 

2C24  Other  loading  conditions: (a)    Vertical loading on walls should be distributed. This may be assumed for concrete floor slabs, precast concrete floors, and timber floors designed in accordance with section 2B, and where the bearing length for lintels is 150mm or greater. Where a lintel has a clear span of 1200mm or less the bearing length may be reduced to 100mm.

[Temp]

I assume this is just a lintel above a window and its not carrying any abnormal loads from steel ridge beams or ?? Otherwise someone should check the loading is ok. I mean 1,000,000 tons on 100mm of bath sponge ain't going to work even if the regs allow it ?