Some years ago an old fancier living in my district raced his youngsters to a little aviary which had a wall at the back and wire-netting in front and sides from top to bottom. The place was six feet long by three feet wide, with just a sloping roof over it. Rain blew into it but the floor sloped away slightly from the wall so that the water would drain away as fast as it went in. I copied this fancier's idea at my own home thirty years ago and I got some extra good results. Later I altered things and made a more elaborate loft, but I never had such excellent results with youngsters.
Taken from Lofts for Racing Pigeons
By Chas. Heitzman
Fifth revised edition