Treble Zeist with a double roof

UPDATE August 2012: 1 pair of Great Tits occupied the box on the left, followed by a pair of Swifts which successfully raised chicks.
UPDATE 2014: Swifts nested in both the left and right boxes
UPDATE 2015: These 2 pairs returned and bred. 3 new boxes on another wall were not occupied
UPDATE 2016: All 3 original boxes occupied by Swifts, tweeter moved to 3 new single boxes.
UPDATE 2017: All 3 original boxes and 1 new box occupied
UPDATE 2018: Same as 2017

Contributed by Dick

Some old friends asked me what to do about Swift boxes on their Cambridge house, which is located within a 100 metres of a substantial Swift colony in Chesterton Road.

Click to enlarge

The house has no eaves, and the only available walls face south and east, so we decided to place a row of boxes on the east facing part. Both the sun and the rain could hit the top of the box, with the gutter providing little defence.

The Zeist format seemed most appropriate, and to use space efficiently, we built a single box with 3 chambers.

It has a double roof, made of 2 sheets of  marine ply separated by batons. The roof assembly comes off in one piece by removing 4 screws along the front into batons screwed to the inside of the roof.

Computer model showing how the roof assembly is fitted

The whole thing was first coated in clear Ronseal, followed by a coating of decking oil, which should mitigate the effects of ultra violet light.