Rebuilding Interior

Rick · Post by **Rick** » Mon Jun 18, 2007 11:22 am

I've removed the old wooden interior of my A21. I leveled the boat and installed the vberth bulkheads. I was lining up the location for the foam and glass stringers along the hull when I discovered that the old vberth was not level. It's higher in the bow - a few inches over the span. Is this standard? My question is whether I should copy the prior installation, or would you recommend that it be level? I may run into similar issues with the starboard and port bunks and elsewhere, so I'll ask now whether there is any reason to deviate from level in these other interior structures? For instance, I am planning to install a wooden ceiling above the vberth parallel to the top of the cabin. Is there any reason to make them horizontal instead? I expect that they will look better if they follow the lines of the cabin, but I'd appreciate your thoughts. Thanks.

Rick

Post by **Tim** » Mon Jun 18, 2007 1:05 pm

It's common to find berths and settees that are out of level. This doesn't mean it's a good thing.

Berths that are higher in the feet are uncomfortable for sleeping, so I'd suggest that you go ahead and install your new structure level. I can't see any reason why it'd be necessary or better for anything to be out of level; usually, it's simply a result of the less-than-careful production methods used by most low or mid-end production builders.

For the ceiling, I think the strips should run parallel to the top of the cabin, not the berth surface. I think it'd look very odd to have it the other way.

CharlieJ · Post by **CharlieJ** » Mon Jun 18, 2007 2:41 pm

In this instance I disagree Tim. It's a 21 foot boat- when two people are in that Vee berth the boat will be riding bow down a bit- HAS to because of the weight. I'd leave the foot up just a tad so when it's in use, it's level.

On a bigger boat I'd agree, in this case no.

Also, on our boat we ran the ceiling parallel with the berth top. I think it looks really nice like that- It's sort of a matter of choice.

Here's a shot without the cushions, showing how the ceilings end under the deck.

Rick · Post by **Rick** » Mon Jun 18, 2007 3:01 pm

Thanks for the quick replies Tim and Charlie - interesting perspectives. Regarding the ceiling slats, Charlie's looks great, but the top of mine will be more exposed, so I'll probably parallel the overhead and hide the transition pieces near the berth where they will be covered by the cushions. The angle of the vberth is still up in the air. Four of us will be in the boat with two kids in the vberth, so I don't know how much the bow will drop - especially since the kids tend to spin around in their sleep like the tasmanian devil! The original raised berth in the bow actually may be more parallel with the overhead. I'll compare the visual effects in the boat later today. Thanks again.

CharlieJ · Post by **CharlieJ** » Mon Jun 18, 2007 4:42 pm

Rick - what isn't shown in the second picture is a trim piece up under the deck to cover all those ends. There's also a vertical trim piece fore and aft covering the very ends of all the ceiling strips. You can just make the end trim out in the first pic, right up against the forward bulkhead.

The wood is all varnished Ash by the way. We like the lightness of ash over darker woods.

And yeah- the differing perspectives is one of the great things about these forums- you can see a lot of different ideas and make up you own mind as to what works in your own boat. Besides- wouldn't it be a dull world if we all did our boats ( and our lives) exactly the same?

Post by **Tim** » Mon Jun 18, 2007 5:06 pm

Good point, Charlie.

Still, with a level berth at rest, if the bow went down with occupants in the berth, at least their feet would be lower than their heads, which I think is more comfortable than head down. But level when occupied would be best.

And the ceiling strip direction is certainly up to personal choice and the individual boat's characteristics; I shouldn't have sounded so unequivocal earlier.

To that end, here's a photo of one I did with the strips parallel to the underside of the deck. When the cushion is in place, the transitions are completely hidden, so I didn't bother making angled cuts to accommodate the berth surface.

In this case, the wood is cypress, finished with tung oil.

Rick · Post by **Rick** » Mon Jun 18, 2007 5:49 pm

This topic reminds me of a funny story when my wife & I rented a small cabin on Mt Desert Island several years ago. The price was great and the owners were also. We rented it site unseen. The cabin was great, with fresh lobster off the owner's boat. The only issue was a slight problem in the rear bedroom. The cabin had settled and the foot of the bed was over 6 inches lower than the head. It felt like you had to hold on to the sheets. Not very restful. We awoke in the middle of the night to a loud crash when my Irish Setter (who always slept on the foot of the bed) rolled off onto the floor.

Thanks for the photos and advice.

CharlieJ · Post by **CharlieJ** » Mon Jun 18, 2007 6:38 pm

Looks really nice Tim. I like the white paint in the footwell also. HATE dark interiors in boats- makes me feel like I'm in a cave when it's rainy.

As to the ceilings which ever way they run, going into a boat without them makes me feel like I'm looking at an unfinished boat. They sure finish off the insides don't they?

cliffg · Post by **cliffg** » Tue Jun 19, 2007 12:37 pm

The photos raise a question. You didn't leave a space between each strip. I had always thought there needed to be one to accomdate the inevitable swelling and shrinking of the wood.

CharlieJ · Post by **CharlieJ** » Tue Jun 19, 2007 3:02 pm

on ours, there is a 1/16th gap between each strip.

Quetzalsailor · Post by **Quetzalsailor** » Tue Jun 19, 2007 4:58 pm

The gaps in the ceiling are for ventilation as well as to accomodate across the grain width changing with the seasons. Ventilation was desirable on wood framed hulls, less important, now. Tradition has the slats parallel with the sheer, and the planking, but, hey!, it's your boat and your eye.

I suppose the slats run through behind the furniture on a wood boat but are more often just decoration in show areas on a plastic boat. Continuous would be easier to install from a nice sweeping curve point of view.

Sloping the vee berth just a bit gives you a tad more length in the bunk. Ours is quite high off the sole for that reason. Tough to clamber in to at my size!

Nice looking work! How'd you like working with Cypress? My experience was building a harpsichord. The exterior of the case is 1/4" thick bent to the shape on the bentside and flat on the others. I ran mouldings for the top and bottom edges out of the same stock using a jig and router. The stuff tended to fuzz rather than cut, but happily could be sanded clean pretty easily.

Post by **Tim** » Tue Jun 19, 2007 6:28 pm

I believe there was a very slight gap between my cypress ceiling boards, but not too much. The amount of movement in this sort of material is minimal, I think. I didn't specifically space them a set distance, though. I haven't heard of any problems with this particular installation.

I like cypress a lot. It's inexpensive and, as a soft wood, easy to work with; it has a pleasing color and grain. Plus, it's relatively resistant to rot, though that's hardly an issue with a cosmetic interior hull ceiling.

Another nice ceiling material is white cedar.

dkall · Post by **dkall** » Thu Jun 21, 2007 8:07 pm

Sorry I don't have any pics but on our last boat in the bow we used 3-4 business cards for the stern part of the slats and one business cards for the forward part. The slight slopping change with the curve of the bow was quite pleasant. I didn't think this up, got it from some older boat building books about having the slats sweep forward. At least that is what I remember.

BristolJonny · Post by **BristolJonny** » Wed Apr 08, 2009 7:42 pm

I know this is an old thread, but I am thinking of adding a wooden slat ceiling to my Bristol 27, and really like the look of Tim's cyprus slats. My question is did you insulate between the hull and the ceiling or is there just airspace there? I don't necessarily NEED insulation, but I want to avoid condensation and mold at all costs! By the way it looks great!

Post by **Tim** » Thu Apr 09, 2009 6:17 am

There is just airspace there, but the slats are held far enough away from the hull to promote good airflow behind.

It's be easy to add insulation there if you want, though, and in many cases that would make sense.

BristolJonny · Post by **BristolJonny** » Thu Apr 09, 2009 9:15 am

So if I decided to put insulation, has it been established whether I need airspace between the insulation and the ceiling? Or what about airspace between the hull and insulation?
From researching it seems that there are many opinions on what is correct, but I would like some firsthand knowledge about which methods fought off mold and mildew and which ones harbored it. Thanks!

Post by **Tim** » Thu Apr 09, 2009 10:13 am

I think airflow is always critical and should always be accommodated.

Hirilondë · Post by **Hirilondë** » Thu Apr 09, 2009 11:04 am

Ceiling was invented specifically because it allowed air flow. Granted, it is a slightly different application on a wooden boat, but not so different. I suggest a slight spacing between slats as well as space behind them, with or without insulation.

Rachel · Post by **Rachel** » Thu Apr 09, 2009 12:26 pm

I'm not sure whether I would install insulation behind celiings at all, as I do like airflow; however if I did I think I would want no airflow at all.

My thinking behind this is comparing to a house: There, if you make an unvented roof, you want the insulation installed tightly and with no air gaps (or as few as possible). This minimized the ability of warm air /moisture getting to the cold interior surface of the roof sheathing and condensing there to cause problems.

On the other hand, with a traditional vented roof, you want lots of ventilation on the cold side of the insulation, like with an old-fashioned attic (which to me would mean between the insulation and the hull, not between the insulation and the ceiling boards.

Again, I'm just thinking about this from when I was building my cabin, and I may have missed something important about boats. Also, I'm only musing about fiberglass boats, which have much less need for air to keep them from rotting.

Okay, tell me why I'm wrong :D

Rachel

Hirilondë · Post by **Hirilondë** » Thu Apr 09, 2009 4:33 pm

Rachel wrote: My thinking behind this is comparing to a house: There, if you make an unvented roof, you want the insulation installed tightly and with no air gaps (or as few as possible). This minimized the ability of warm air /moisture getting to the cold interior surface of the roof sheathing and condensing there to cause problems.

If you don't vent your roof it will cook and dry rot much faster than it should anyway. Bad idea. The building inspector should fail you at the structural inspection and make you do it over, if he is paying attention. Ventilation is required by code.

Oscar · Post by **Oscar** » Thu Apr 09, 2009 4:35 pm

Unless you're using a stress panel or similar. Ventilation is good......

Rachel · Post by **Rachel** » Thu Apr 09, 2009 6:49 pm

Dave,

I actually got the idea from several reputable building books. Inspectors had no issues with it. I think it's actually a valid approach for certain houses (and done right, of course).

Here's a link to City of St. Paul, Minnesota, gov't guideline on non-vented roofs, if you're interested. They do say that venting is preferable, but that if you can't vent properly, an unvented roof is a viable alternative:

http://www.stpaul.gov/DocumentView.asp?DID=1551

In my case it was a small structure (18' x 20') and had a gable roof with a loft. Now if it had had a full attic for ventilation that would have been great. But sometimes (in houses in cold climates) a little inadequate ventilation is worse than none at all (in my opinion, but I don't think I'm totally alone here).

The roof in question was very carefully moisture barriered from the inside, then filled with extruded polystyrene to a pretty healthy R-value, then sheathed and roofed. It had a decent slope and a simple shape (gable, no dormers, chimneys, or valleys).

But back to boats, I know that CharlieJ here (actually his wife, Laura) ceiled his boat with insulation behind it. I believe he used 1/2" ply for the "frames," then filled with 1/2" isocyanurate, and topped with closely spaced ash slats (so there is no ventilation). I wonder if he's removed his, and how it's faring?

I think it would be fairly hard to both insulate and provide air space in the size boats most of us have, so if you are choosing to insulate, you might have to forgo venting (not on a wooden boat, of course).

Rachel

Hirilondë · Post by **Hirilondë** » Thu Apr 09, 2009 7:31 pm

There are ways to ventilate that don't require an attic. And ventilation isn't just for moisture but to reduce heat from direct sunlight. Roof shingles melt if they get above 160 degrees. Plywood bakes and crumbles from heat alone. Channels are fabricated under the plywood above the insulation and vented from below with soffet screen and at the top with ridge vent. No attic is needed. If you build with conventional materials I think it is irresponsible not to ventilate, even if you can get by an inspection.

Rachel · Post by **Rachel** » Thu Apr 09, 2009 9:15 pm

Dave,

I did know about the channels, and consider them, but ultimately decided that for my structure and climate (far northern Minnesota) the way I went would be better. One example of a factor I took into consideration is that ridge vents often get blocked by the large amount of snowfall there. I can appreciate what you're saying about plywood baking if it is directly under asphalt roofing shingles; my roof consisted of plywood sheathing, tarpaper, furring strips and then a metal roof on top. So the roofing was not right on top of the sheathing.

I should note that while my research at that time indicated that this was a viable alternative, and while I am not aware of any code restrictions that indicated against my methods then, and in that location, things may have changed (e.g. I also used the "airtight drywall" approach for the walls, and I'm not sure that's a current method anymore). So I'm not recommending un-vented roofs for anyone now; I was just comparing the concept as it applied to insulated boat ceiling that might not have an air gap behind it.

But like many things in boats, there was no perfect way. When everything was considered and weighed, I went with what I thought was best and most prudent for the situation.

Rachel

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