Raising your timber system as a retrofit may accentuate any imperfections that occurred during the building process of the existing structure. Any variation in room spans, wall planes, roof planes, and/or pitches can cause gapping in a retrofit timber system. Also, without typical conventionally raised timber joinery to resist wood’s natural movement during the drying process, a retrofit timber system can gap over time. Caulking, puttying, and trim work are possible options to conceal these imperfections.
It is suggested that on any retrofit system, representatives from Harmony Timberworks come to your site to do an analysis of the project and pull field measurements on a fee basis. Your construction team may not be fully aware of the intricate information needed by our design staff in order to prepare a system model. A visit from our crew can assure that all necessary information is acquired.
Sufficiently connecting retrofit timbers to an existing structure is important. Installation of blocking (see “Blocking” section) will typically need to be installed prior to timber delivery. Allow for this additional material and labor in your construction schedule. Typically, the raising sequence for a retrofit roof system is to first rigidly attach the timber rafters to the existing structure, then to hang the remaining timbers individually from the timber rafters. As noted above, connection details to existing structure will only be provided by Harmony Timberworks if you choose for us to have your structural plans reviewed by our engineer.
The raising process of a retrofit will go much slower than that of a conventionally raised timber system. With a retrofit, pre-assembly and craning in of the timbers is not possible. Most likely, each timber will have to be raised individually by hand. This may not be easy. Example: A 6”x10”x16’ Douglas fir timber will weigh approximately 320 pounds. The estimated weight of your timber system components will be noted on your Harmony Timberworks timber plans.