Our standard designs – R1, plain-ended or tapered; R2, plain-ended
with integral keystone; and R3, tapered with integral keystone – suit a
three-brick course height in a normal cavity-wall situation. They are
available in the following lengths to suit British Standard brick openings:

R1, R2, R3
460mm (18 1/8")	910mm (351 3/16")	1248mm (49 1/8")	1585mm (62 3/8")*
685mm (26 15/16")	1135mm (441 1/16")	1360mm (53 9/16")	1810mm (71 1/4")*
*Only supplied as a two-piece head, left-hand end of R2 and R3 incorporating keystone.

Please note that other head sizes can be manufactured to order.
Supporting lintels must be used as these window heads are not structural members.
We strongly recommend that you refer to BS 5628 Part 3: 2005.

R3 Head with P2 Cill

Our two standard designs P1 and P2 suit one and two-brick course heights respectively in a normal cavity-wall situation. They are available in the following lengths to suit British Standard brick openings:

P1		P2
460mm (18 1/8")	1248mm (49 1/8")*	460mm (18 1/8")	1248mm (49 1/8")
685mm (26 15/16")	1360mm (53 9/16")*	685mm (26 15/16")	1360mm (53 9/16")
910mm (35 13/16")	1585mm (62 3/8")*	910mm (35 13/16")	1585mm (62 3/8")*
1135mm (44 11/16")**	1810mm (71 1/4")*	1135mm (44 11/16")	1810mm (71 1/4")*
Note: Dimensions exclude stooling - maximum 100mm (3 15/16") at each end.
*Only supplied as a two-piece cill.
** One-piece only when supplied without stools.

We have three standard designs: Q900A, Q910A and Q920A.
Please note that other keystones can be manufactured to individual requirements.