Masterframe Trade Logo

Traditionally, the lower rail of the bottom sash was made from 4″ or 5″ timbers, planned to about 100mm. This was substantially heavier (deeper) than the side members or mid-rail because it had to carry more weight than the upper sash.

While it is far quicker, less expensive, and easier to weld profiles of equal size, welded and grooved corners do not look traditional, so deep bottom rails on all our product ranges are mechanically joined as standard.

Vintage, Heritage and Authentic sash windows all come with a deep bottom rail as standard.