I saw this in an attic in a 1958 bungalow. It looks like a tin barrel with a vent or fill tub that extends to the underside of the roof deck. The roof is obviously not the original roof and there was no visible penetration on the exterior surface. I am sure it has been decommissioned but I have no idea what/why it was originally installed in the home. (as it would definitely not fit on the hatch) You will note it is insulated and it has a bearing wall below it. I was thinking it may have been a rudimentary solar exchanger but see no evidence of anything unusual in the utility room. Any help would be appreciated!
My first thought was a cistern to catch roof run off. Situated over a bearing wall would be correct in the mind of a do-it-yourselfer. Is there any indication of a previous cut in the sheathing now covered by replacement shingles? Has some sheathing been replaced? Any chance of a previous owner with a possible answer?
Can you check under the kitchen base cabinets for a disused water supply or capped plumbing stub?
I have found three hidden cisterns in older homes. One under a work bench in the basement, one under the basement cement floor fed by a gutter downspout and one under a front porch.
Thanks Bryce, I won’t have access until my client takes possession in early June. I will update when I get a chance to do some further investigation. The good news is that hte client is planning extensive renovations so I am hopeful we will get some clarity on what this thing is/was.