Warming your timbers

Case no. 913 has us examining the home owned by one Alison Shiver, along with her husband, M.E. (Michael Eliot) Timbers.

Together, they own and operate ‘Shiver Me Timbers’, taking advantage of this match made in heaven to become the new owners of the local ice cube and ice block company, formally owned by retired seaman L. J. Silver. With over one million cubes of ice being manufactured daily, the Shiver Me Timbers people know how to make and bag ice. Incredibly though, the Shiver Me Timbers company still ranks second in ice production to an element that’s thankfully not a retail competitor of theirs. Who might this element be? Oddly enough, it’s the roof right over their heads.

Alison and Michael’s roof produces icicles, which unfortunately due to the rather stringent laws regarding the use of petroleum oils and granular roof matter in foodstuffs, prevents these icicles from being bagged and sold as a natural after school treat. So, with no profit to be made by harvesting these icy daggers, or added benefit of introducing “Icy Roof Treats” to the company’s line of products, it’s time to eliminate this obvious display of home inefficiency.

Regardless of how charming icicles look in a Hallmark Christmas card, they’re a sign of heat loss. Heat loss in a home is going to happen. We lose heat through our windows, our mechanical exhaust vents, and every time somebody opens a door. Those heat losses are inevitable, not so controllable, and other than having a bunch of poorly operating windows, are no real cause for immediate concern.

However, a warm attic in the thick of winter is not a good thing. Essentially, your attic is going to end up catching a cold. Heat being produced in the home naturally rises up. If this heat, and accompanying moisture, is allowed to infiltrate the attic, it’ll continue up towards the plywood or roof plank underlay. When the plywood warms up, heat gets transferred to the shingles overtop, which melts the snow. This snow melt then races down the roof until it reaches the overhang, the only part of the roof that’s cold because it has no heat source underneath. When the snow melt crosses the overhang, it begins to cool, then freeze, just as it’s attempting its leap off the roof, forming the not so cherished icicle.

Unfortunately, hanging shards of ice will be the least of your worries. If the snow melt fails to make its way to the edge of the roof, it’ll join the ranks of the other icicle wannabes, and become a member of an even more notorious group, known simply as the ice dam bad boys. When heat is allowed to rise into the attic, condensation often forms on the plywood. Now you’ve got a couple of water sources in your attic, one as a result of an ice dam forcing snow melt back up and under the shingles, along with moisture dripping down from the plywood underlay.

Two bad things about these scenarios. One, wet plywood eventually rots. And two, the condensation drippings will fall into whatever insulation you have in the attic, lessening its thermal value, forming mold, and eventually making its way to the ceiling’s drywall. So, how do we keep our attics nice and cold in the winter? By sealing any breach in the ceiling’s drywall, removing any heat sources, and most of all, by insulating.

Start by removing the decorative collar around any hanging light fixtures and ceiling exhaust vents. Sometimes, the drywall cut around the electrical box, or ductwork, isn’t so perfect, which will allow moist air to draft up into the attic. So, seal this gap (if it’s a 1/4 inch or less) with an ‘acoustic-seal’ caulking. Larger gaps can be filled with a ‘Gaps n’ Cracks’ spray foam. Next, make sure any ductwork or venting pipes running through the attic are insulated, and, that they’re not exhausting directly into your attic space.

Next week, we’re insulating our attic. Good building.

As published by the Standard-Freeholder
Handyman's Hints Standard-Freeholder Cornwall Ontario by Chris Emard

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