Cabin/Pilothouse Rebuild Advice?

I could use some good advice on how to rebuild (replace) the cabin top and pilothouse on a 45' ferro-cement Hartley Tahitian sloop. My background is construction - I can build houses from trees - but I don't want to attempt to transfer home building and remodeling skills to the marine environment and have it wash off when a big wave slams me.

Links, photos, descriptions, and other examples of what I should do (as well as what I should NOT do) would be greatly appreciated. I'll be using mostly SS fasteners but not sure what species of wood to use - Yellow Pine, Oak, Pressure Treated? 1"? 5/4"? 2"? What adhesives to tie wood superstructure to cement side decks? 5200? Life-Caulk? Liquid Nails? If I can't afford some sort of fiber sheet goods for the top and sides, I'll be using plywood. Advice on marine grades or suitable alternatives?

Thanks.

John

Here's what the finished product should look like:

 

I'll just repeat what I've already mentioned on another site . . .

It's always difficult to "attach" to ferro builds. The best method is creating a flange in the concrete, then bedding a mating structure to the flange, using through bolts.

Don't even think about Liquid Nails. It has no business on a boat. For that matter, most of the stuff you're used to working with (PT, OSB, etc.) have little use on a boat.

Considering the size of the areas you'll be replacing, you will not need much plywood, so opting for a quality marine grade is just good business sense.

Yellow pine and oak (the whites, not the reds) are good lumber choices. You could do everything in SYP which is as good as many hardwoods and more rot resistant.

Eventually you'll get to a point where it'll need to be sheathed in something to protect it from abrasion and waterproof it. Epoxy and 'glass are really the only choices you have if you want resale value and durability.

In the end, much more without an idea what you're working with will be difficult.

If it was me, I'd cut the current pilothouse and cabin roof off. Leaving a ferro lip at the cut line. This lip would need to be sealed and I'd use epoxy for this. I'd then build a "shoe box" (cabin roof) or other style of flanged attachment for the new structure. The new structure would be all plywood, maybe with a few roof beams tossed in, particularly at the mast partners, fore and aft ends of the cabin, bulkheads, etc.

The pilothouse looks simple enough, some sticks in the corners, with a plywood skin. Maybe a real stud wall system, insulation, wiring, plumbing, etc. An exterior skin of 1/2" with an interior of 1/4", maybe painted bead board for a special look.

Are the cabin and pilothouse ferro?

 

Par's advice is right on the money. You should also consider purchasing a copy of Bruce Bingham's "Ferro-cement Design, Techniques and Application" as it is a treasure trove of information, drawings etc... specifically for the ferro-cement or Fer-A-Lite boat owner.

We are nearing completion (I hope) of the replacement of the cabin roof and the addition of a pilot house on our Samson C-Ranger.