Antique post-and-beam Colonial roof insulation
Looking for feedback on my antique colonial regarding insulating the roof. It is a large post and beam home built in the 1820’s in a suburb of Boston. The whole house: roof, walls, basement, currently have no insulation. I am renovating the home and plan to insulate it. About half the roof line acts as the sloped ceiling to the third floor (which is finished) and the other half is unfinished attic. There are two gable end vents providing airflow through the attic. My current plan is to remove the vents and clapboard over the holes. Then insulate between the plaster and lathe of the third floor ceiling with blown in cellulose, while spraying the exposed attic with open cell spray foam. Should I be concerned about using two different types of insulation in this system especially considering I am removing the gable vents? Should I just remove the plaster on the third floor and spray that as well? It is a great old house and the condition of the beams in the roof are perfect, I dont want to do anything to compromise them. Thank you.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part