Brandon Nelson
Call
FAX
Categories
- Neighborhoods
- Structures I Love
- NW Street Views
- Seller Info
- Buyer Info
- Market Info
- NW Way of Life
- NW 'Words' of Life
- Home Projects & Upkeep
- Races & Events
- Other Stuff
Neighborhoods
Bellingham Weather
There’s a Lake on My Roof!
I often quote a renowned building performance expert named Joseph Lstiburek, on his two rules for ideal exterior design in wet climates:
One, “If you want to save cash, flash!”
And two, “Don’t be a dope, slope!”
I’ve seen plenty of instances where both rules are broken. For example, rather than flash a joint between two materials, such as where siding meets a deck ledger, some people will just intall a bead of caulk and call it a day.
Does that work? No. No, it doesn’t — it needs metal flashing.
I’ve also seen plenty of flat, horizontal surfaces that don’t shed water, such as poorly drained flat roofs. There are a lot of places in the world where flat roofs work just fine, where the rainfall is relatively minimal and the heat of the sun bakes off any standing water faster than you can say, “Death Valley!”
But the Pacific NW is not one of those areas. Here, one could almost truthfully say, “If it doesn’t drain, it doesn’t dry!”
So, if your house has a flat roof, get out the ladder and hike on up there a day or two fter the next good rain. Is there a lake up there? If so, you’ve got a situation, pardner. And you’ve got two choices:
One, fix the drainage. Are there scupper or other drain-holes for water to escape? If so, are they clogged? If there aren’t any, there needs to be. If they’re there, but the water is elsewhere, guess what? The two must meet.
Two, if fixing the drainage isn’t a possibility for whatever reason, then you need to get some slope so the water can shed, like it does on a gable roof. It’s possible to maintain the flat roof “look” of the home while getting enough slope built in to get the water running downhill and off the surface. That’s the goal.
Water that just sits on the roof like a lake will eventually find its way into the structure, where it will leak into the interior, and cause rot and mold and all sorts of nasties. And the sheer weight of it is hard on the house. A 20 foot by 20 foot lake of water 1 inch deep weighs a ton. Imagine if it’s two inches deep. Full size trucks weigh less.
If you’ve got a flat roof, climb on up there and check it out. If there’s a lake, and if you need a referral to a roofer or a general contractor, give me a ring. I’ll put you in touch with the right people.
