Condensation in VBerth

[George Emery]

My wife and I have lived aboard for seven years in the Pacific Northwest. We used several products but the moisture barrier for outdoor furniture cushions works the best. Fabric stores sell it and it is not that costly.

[sartorst]

Thanks that it! Cheechako

[ardoin]

I have insulation above the water line. That keeps most condensation away. I don't think it would be practical to add it after construction. It was a nice surprise to find that the original owner had paid the $$$ to have it built into the boat.

[Bash]

You won't find an easy fix, especially when it's raining or during a cold snap. I recommend dri-dek panels PLUS a dehumidifier. We sleep with a Soleus dehumidifier in our stateroom all winter. The reason we like that particular brand is because it's more quiet than anything else we've tried.

[CarinaPDX]

I use Dri-Dek under my v-berth, and it works well. The newer HyperVent is lighter, and should also be easier to move to access under the cushion, so that is the way I would go now.

The condensation under the mattress is a direct result of the perspiration of the body on top migrating through the foam. Providing an airspace under the mattress allows the moisture to evaporate and at least spread out. Even with the space, it is a good idea to tip up the mattress during the day so that it can dry out.

Condensation dripping off the overhead, hatches, portlights, etc is a related problem. The moisture put in the air by the bodies inside the boat plus the cooking and combustion hitting cold surfaces is the cause. The only solution is to keep the boat well ventilated. The natural reaction to cold is to close the boat up, but that is potentially disastrous. In addition to the damp, mildew will become a problem. And it is hard to get warm when damp. So turn the heat up higher than you need and move the damp air out quickly.

Greg

[senormechanico]

Originally Posted by ardoin

Another vote here for Hypervent!

And another.

[tmiller1116]

we live aboard a 30' in the PNW and use a Soleus dehumidifier in the main cabin, dri-deck under the mattress , have the edge of the mattress propped up slightly so air can flow at all times AND have a spare electric heater set on very low supported in the v-berth area.

We still find that condensation occurs in the storage area under the chain locker (right at the foot of the v-berth, and we leave it open all the time) then runs down and pools under the mattress until it finally drips into the area next to the water tank. Right at the foot of our covers we get some build up as well.

Every day we roll the covers back away from the bulkhead to dry out the little that gets on them and at least once a week pull up the mattresses to let them dry. This is the only place on the boat that has issues unless we leave something crammed up against the bulkhead where air cannot circulate.

I am beginning to feel it is just the price you pay

[thinwater]

In the summer, all of the ventilation tips are good.

Since it started in the winter, it is cold working its way up. Insulate the surface; that is the cause, everything else is patchwork.

[Sam Plan B]

You have a problem with your body vapor passing through your matress and condensing on the GRP surface of your V berth. You need to prevent the moisture migration and prevent the cold surface below acting as a condensing plate. Buy two 4'x8' sheets of Blueboard brand Styrofoam insulation. Cut them using your V berth matress as a pattern. Lay them in the V berth. Next cut a V shaped piece of 6 mil polyethlene sheet and lay it on the Blueboard. The poly will act as a vapor barrier to keep the moisture from migrating. The Blueboard will keep the cold GRP surface isolated from the poly. As for condensation on the overhead and hull, I use a SoleusAir dehumidifier. It pulls about a gallon of water out of the air over night. I do have to keep the cabin temp above 40F. That is not a problem with my electric blanket one over weight cat.

[FlyMeAway]

I live aboard in the Pacific Northwest, and I too have condensation problems under my v-berth. I've solved the problem by tipping up both the mattresses (butterfly style) each day before I leave the boat, and place a 90-watt West Marine "dryer" near the mattress I sleep on.

But I also do not have any other condensation or mildew issues in spite of living in a cool, wet climate. I NEVER let the temperature of my boat fall below 64 degrees, and the daytime temperatures are pretty much always in the high 60s / low 70s unless it is quite cold (below 36 degrees) out. I use 2 standard, residential-quality Vornado fan heaters on their lowest setting (750 watts) to keep air circulating. They run 24/7. Then I have hydronic and a thermostat as a back-up for the colder months. This is enough for my 36-footer (typical monthly energy costs in the dead of winter are $75).

While others liveaboards in my marina have serious condensation / mildew issues, I have none and can't really imagine having any. I actually don't understand why this is such a problem.

[JPA Cate]

We have successfully combated this problem in two ways:
1) Cheapest: buy 6 woven sea grass doormats. Link them together with 1/8" loops of "string", diameter, about 1-1/2". One to each side of forepeak. This is enough to allow air circulation and no more mildew will happen.

2) If you dont like the smell of the sea grass (Jim didn't), then buy some 1/8" thick closed cell foam and place it inside the cushion, underneath the foam--we used spray adhesive to go directly to the foam, but I think just putting the closed cell foam next to the bottom will do the trick--and the mildew quits happening. Obviously, if the foam is now moisture soaked, you'll have to take it home and dry it first, but if all you're dealing with is condensation, not true leaks, both of these methods have worked for us, and low cost.