I am a retired structural engineer from England. My American son in law is considering modernising a 100yr old framed house. Can anyone tell me whether roofs of this age (in NY state) will be of a truss variety or posts supporting purlins? Or were both methods used?

Hi David,

There are several types...and staying within the historic format is usually appropriate for Heritage Architecture. Modernization of these vintage homes often leaves them not the same and seldom improved. Many here would love to help in any way they can. Photos would really help, and what the final goals are.

Regards,

j

Does your S in L not know what the roof is comprised of?

Houses of that era were usually not built with roof trusses, and often rely on posts or kickers from interior load bearing walls to support the rafters at mid-span or thereabouts. A quick peak in the attic should tell all.

In the mid-Atlantic states, hundred year old houses are usually not timber framed but rather balloon framed. Small roofs are not commonly constructed with structural ridges, principal purlins nor principal rafters with common purlins. Rather roofs are common rafter couples tied by ceiling joist. Expect simple butted and nailed joints. As buildings scale up in size, more advanced technique comes in play.

Thanks to all,
I was wanting to keep my initial post to the minimum, for brevity.
The property is one that my S in L is considering buying; I am considering ways of modernising the second floor, and propose knocking through an existing internal wall, roughly at the centre of the building. I understand that a look in the attic would show up any conflict, but we are not at that stage yet. Thanks anyway.