With the
roofing finished, and smaller tasks like
painting underway, completing the exterior of the dormer is probably the last major element of exterior work before the scaffolding can come down. As with most things on this project, I originally did not think it would take too long to complete...but of course it did.
I had never done any exterior carpentry & finishing before, so there was a steep learning curve - and I ended up with a new-found appreciation for, and understanding of, what goes into doing this work well.
By "trimming-out" the dormer, I'm referring to building the part the facade that will surround the
windows & doors - this type of woodwork is called "trim", and here, it will ultimately be painted. As the facade is not structural, its main purpose is to keep the water out, which in England is a major task! Normally, having painted wood exterior trim is frowned upon here because of all the rain and dampness - if you use paint, you generally have to re-paint every year or so. In most buildings, one would normally need scaffolding to access these areas for repainting, so more durable (and very expensive) materials such as lead are normally used. But because there's going to be a
Juliet balcony in front of the dormer, I figured we could save a lot of money and some construction time by using wood and then re-painting every year.
The base of the trim-work was actually started in between other tasks, and during the roofing and slate work. After finishing the
ridge tiles in the early afternoon of June 20th, I used the rest of the day to build-out the vertical portion of the dormers edge.
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| June 20th |
After that, I managed to do a few little things here and there, but it was only on the 24th that I was able to focus completely on it. As you'll see, most of the wider trim is plywood - actually waterproof plywood (18mm WPBP) that is screwed into the dormer structure and edge battens for the slates. Then smaller planks of pine are used to frame the opening for the future windows and doors.
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| June 22nd |
Part of the challenge here is that the design of the trim had to utilize the lead flashing detail I developed to span between the
slate roof and the modern membrane roof. Roof and wall systems (whether modern or traditional) are always designed to allow water to drip down without hitting the building face. As an architect, I had always drawn these details, but it was completely different to see these principles in action, while building them.
The final design is basically like a series of overhanging elements - each with their own drip edge until we get to the window. So there are several layers of protection - almost like an upside down wedding cake. After several days, the dormer finally began to take its final shape, and by June 27th with the trim finished, the end of the exterior work was finally feeling close...
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| June 24th - completed the plywood that forms the roof's edge |
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| Starting the trim that covers the dormer's structure |
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| The main drip edge completed, with the window trim in progress |
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| June 25th - the window trim almost finished |
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| Supporting strips of wood for an exterior piece |
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| The window side is completed |
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| Applying a waterproof chemical to the wood - this is the foundation for the primer & paint |
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| June 27th - Doing the final trim around where the balcony doors will go |
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| Trim around the door opening completed |
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| The finished trim. Now onto filling the holes with wood putty, primer and painting... |
