Under Cover for Winter

This will be our fourth year wintering on our boat, and each winter so far we have put up a cover only to find that there were things we would like to improve. The first year we left the mast up and the frame was not well spaced – and we had the ice storm. That year we kept making repairs as icicles fell of the rigging and the cover collected snow and ice and sagged in some places. The second year our frame was a little too light and very flexible and the string that ran under the keel and was supposed to hold the plastic down rode up, encouraged by the shape of the underside of the boat. That cover moved every time there was a windy day, letting rain and snow underneath and on to the deck. The third year we made the middle support too high and did not fasten the wood along the rub rail that was supposed to hold the cover down down strongly enough. The wind got underneath and tried to lift the whole thing up several times.

To sum up: the challenges, we learned, were to build a cover that stands up to the wind, does not allow snow or rain to accumulate, gives us space to go forward along the deck to do things like put water into our tanks or tighten dock lines, and stays down and in place in even the windiest conditions. Each year we’ve managed to do a little better by solving the problems of the year before, and this winter we planned to keep improving.

Over the summer Richard had time to consider what he could do differently, particularly to keep the cover as a whole in place. By this fall he had decided on a way to fasten the cover down more securely. He started by using metal brackets to fasten a foundation of 1 x 3 pieces of wood, outside and alongside the rub rails, to the stanchion bases.

Here is a picture of how he did it:

Winter cover detail, photo by M. Mair

At the bottom you can see the metal bracket holding the lower part of the frame to the stanchion base. Photo by M. Mair

On top of that a wooden foundation he built a low frame of 1 x 2s. He screwed uprights on to the foundation 1 x 3s beside each stanchion. They are about the same height as the stanchions, except for the longer ones where he wanted the door frame. Then he connected the uprights together with horizontal 1 x 2s, creating a solid base for the rest of the cover.

Once that was in place he attached grey plastic conduit pipe to the wooden base with screws, as you can see above. The pipe bends into a curve above the boat. That curve is what keeps the rain from puddling or the snow from collecting on the cover and sheds wind. The lengths of the conduit vary, creating a cover that is highest in the middle of the boat and lowest toward bow and stern.

Wood fastened to conduit, photo, M. Mair

Wood fastened to the conduit with small screws through the pipe and ends of the wood, photo by Margaret Mair

To the conduit ‘ribs’ he attached a 1 x 2 wood ‘backbone’, pieces joined to make it long enough. It runs down the middle of the boat and holds the ribs in place. Lower on the curves he put more horizontal pieces of wood, to help the cover keep that rounded shape. All the wood was attached with screws – that is also new this year.

Frame, photo by M. Mair

Frame with ‘ribs’ and ‘backbone’, photo by Margaret Mair

Once the frame was finished he attached 6 ml plastic: vapour barrier to the pipes with red tape and stapled it to the wood, to cover the boat in. He put red tape over the places where the plastic was stapled to the wood to prevent it from developing holes around the staples. Then he took advantage of every calm, dry hour he found this windy fall to heat and shrink the covering so that there are no dips for rain or snow to accumulate in. Calm and dry because when the plastic is heated it becomes softer and can stretch in the wind and rain prevents it from getting warm enough to soften and shrink.

Vapor barrier, photo by M. Mair

Vapor barrier on frame, not yet shrunk. Photo by Margaret Mair

Then there is the door that makes it easy to climb on and off. The aft side of our door frame is close to the stanchion I can see through the cabin window. It is strengthened and held in place by one brace on the inside of that stanchion and another brace on the forward side that runs to the wooden frame on the other side of the boat. That brace is high enough for there to be space for anyone going forward to duck under easily.

The door itself is made with a wooden frame of 1 x 3s that is kept square by metal brackets. It is a rectangle with a 1 x 2 across the middle where a simple door closer is mounted. We did not design it: three winters ago our neighbour, Jeff, gave us a door he no longer needed to use in that year’s cover. That old door was very practically designed, right down to the way it was kept closed, so we used it as a pattern.

Door latch, outside, photo by M. Mair

Door latch from the outside, photo by Margaret Mair

If you look at the picture of our door closer you’ll see that above the brace in the middle of the door Richard mounted another piece of wood on two blocks to make a narrow opening. The outside handle for the door/slider is a piece of wood long enough to grab easily that fits through that opening. Inside the latch is made of a horizontal piece of wood that slides over the door frame to keep the door closed and slides off the frame when we want to open it. The latch is held in place by a wood block attached below the handle on the outside. A small metal handle on the inside makes opening and closing the door from the deck easy. To make it easier to open and close after the wood swelled Richard just added some washers under the screws as spacers.

Door latch, inside, M. Mair

Door latch from the inside, photo by Margaret Mair

We are almost weathertight now – there are only a few finishing touches left. The door needs rubber to seal it against the frame where the cover is not flat, so that snow will not find it’s way in through any gaps, and the handle needs painting (on the next sunny day that we’re actually here) so that the wood will not swell when it’s wet. But we are already enjoying the warmth under the cover on a sunny day and the pleasure of being able to step inside out of the wind and rain (and soon, it seems, snow).

I guess we’re as ready as we can be.


Written by Margaret Mair, with technical input from Richard Mair

Photos by Margaret Mair

About Margaret Mair

In love with the sensuousness of paint, intoxicated by the rhythm of words, entranced by the world of water, ever an observer and explorer.
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12 Responses to Under Cover for Winter

  1. caro ayre says:

    How about a second layer of bubble wrap to keep you insulated as well as dry! looks amazing, I hope the weather is kind to you.

    • Margaret Mair says:

      I hope the weather is kind too, Caro. We have actually thought about bubble wrap, but putting it up would be a challenge. We’ve also thought about a black cover for the deck, to hold the heat – you’d be amazed at the range of possibilities we’ve considered!

  2. John Cumper says:

    The black cover will be good on a sunny day but will also lose (radiate) more heat than a lighter color on a dark day.

  3. Cory Petrie says:

    Hello, i am looking to live aboard this winter also,how do you reduce condensation inside sailboat over the winter months?
    thanks cory
    SV snowgoose
    hullmaster 31

    • Margaret Mair says:

      Hello, Cory. Condensation is one of the most common problems when living aboard in cold or damp weather. The cover is one way of reducing it – it helps warm the deck and cockpit on sunny days and seems to give enough of an insulating effect to greatly reduce condensation of the kind that drips down on you as you sleep. Other things we do include allowing air to circulate as freely as possible in the boat, trying to heat the whole boat as evenly as possible and creating an air space between cushions and the surface below them (other than that you can lift the cushions up each day so that they dry out). No matter what you do it’s good to check lockers and other spaces for condensation regularly, and wipe out any you find. Hope that helps!

      • Cory Petrie says:

        Hello, thank you for the good info on Condensation, what would be the best way to heat sailboat over winter in Ontario, electric ot dickinson diesel heater?
        thanks cory

      • Margaret Mair says:

        We use electric, since we prefer not to have diesel on the boat. However, you have to buy your heaters carefully (we have two Caframo heaters that work very well for us) and pay attention to how many amps everything uses. The liveaboards that use diesel tend to use heaters that have the combustion units outside the cabin with the heat circulated through the boats through vents (Espar is one). In any case, with a diesel heater, you will need a carbon monoxide detector to make sure you can escape should carbon monoxide build up in the boat – it is a byproduct of the combustion and must be exhausted outside the boat.

        And I should have mentioned in the discussion on condensation that insulating the hull helps a great deal. We’ve used waterproof styrofoam and cork sheet for that.

        Hope that helps!

  4. Cory Petrie says:

    Hello Margaret, i am at Frenchman’s bay for the winter, starting to build winter cover frame, and looking for info on clear plastic, can i use 6 mil Vapour Barrier super seven, from home depot, will this shrink well?
    all info appreciated..

    • Margaret Mair says:

      Hello, Corie – yes, you can use the 6 mil vapour barrier. We have used it successfully. There are a few things to watch out for: use an electric paintstripper type of heat gun (propane is too hot) and don’t try to shrink on a windy day. The hot plastic will stretch! Also tape anywhere you put staples or the plastic will rip.

  5. Cory Petrie says:

    can you heat shrink the plastic together at seams? like a weld?
    or will i need to use tape?

    • Margaret Mair says:

      Yes, you can. Just wear a glove to keep the heat off your hands since you’ll need to press the seam together.

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