Bathroom addition on deck

Hi there.
I am doing up an old timber fishing boat and wanted to add a toilet and shower on the deck. I can’t find anything on line for above deck additions apart from a prefab system.
is this the best option or could I simply build from scratch and if so where can I get design ideas from.
I have heaps of room and space under the deck for pumps and drains etc.

 

Welcome to the Forum Giles.

Have you got any photos of the boat that you can post here for reference?
Or, if the forum will not let you post photos yet (as you only signed up today), you could email me some, and I will post them for you?

If you do not have any photos, what are the approx dimensions of the boat, and what sort of hull shape does she have?

 

A fiberglass shower box can save you a lot of work. However, you will get better answers if you post some photos and dimensions.

 

As you can see from the attached, space is not an issue. We are currently extending the cabin out by 2.5m and pushing the extension to the inside of the existing gunwale and following the existing roof line. I.e. the port and starboard walls will be angled in from bottom to top by approx 15 degrees.
the bathroom will be added on to the stern side of the cabin against the starboard gunwail and so will have also a slightly sloping starboard wall. We don’t know the dimensions for the bathroom yet, but would like to keep them minimal as one of the things we love about the boat is the deck space.

 

Your boat looks very fine Giles.
Do you intend to do commercial work with her, re carrying passengers for hire, like on day cruises or fishing trips?
If so, this might have a say in what standard has to be met re the toilet / shower facilities?

Re how she is timber, are you going to remove that awful green carpet from the deck? Carpet and wooden decks are not very compatible bed fellows.
Re extending the 'cabin out by 2.5 m', I presume that this means you are extending it aft wards by this amount?
And you also mention pushing the extension out to the existing gunwhale - but if you do this, will you still have reasonable access to the midships mooring bollards?

 

What are you actually looking for? Toilet and shower are just that, a room into wich you install your favorite brand of marine toilet. Sink, faucet and shower are just like on land, you can probably even use gravity drainage, but you could do a marine type plumbing.

 

thanks for your reply.
She is purely for pleasure but we will likely have a parties with 20-30 people on board and we want the bathroom to look reasonably professional.
The deck cover is fake grass and is porous so water drains through it. The deck under the cover is fiberglass. We actually really like it. You can sit on it, lie on it and even pitch a tent on it.
You are correct re cabin extension aft wards and I also have concerns about going all the way to the gunwales due to bollard access, but the gunwales are 200mm wide and we intend to fit handrails to the port and starboard walls and add grip material to the gunwales. Do you think this is risky?

 

I would have thought that there is no need to make the cabin house wider - surely there will be enough room within for the heads compartment and other accommodation?
Better surely to run the wheelhouse back at the same width, and maintain those nice wide side decks, along with good access to the midships bollards?

 

Yes that is what I am starting to figure out. I’m really trying to get some ideas of internal flooring and waterproofing plus how to manage waste.
i would think that someone has already done something similar and I’d like to follow someone’s lead rather than making mistakes as I go.

 

Waterproofing depends on how you plan to construct the cabin. The floor is already waterproof, it's the fiberglass deck. What will the walls be made out of? Flooring, etc. depend on what you want, everything goes, even tiles and granite.
Since you have such basic questions, my advice is to consult a NA, you don't want your new cabin ruining the boat by beeing overweight or structurally unsound.

 

what you are planning is pretty standard giles. lost of other cray boats have had the wheel house extended and walk in bathroom added on deck. i had a friend in albany with a 40 ft ex cray done up similar to what you want. the decks are so large on these boats its easy to do stuff like that. is your boat a marko. looks like one but there were a few that looked similar.

 

Sorry for the late reply Brendan. She is a Mews Bros. Id really love to find someone that I can talk to about what materials and finishes they used to do an extension.
I have had estimates that vary significantly from $15k to $70k, but some are proposing fiberglass and gel coats, while others are simply saying to use Dulux paint.
Some say 18mm marine ply, others say 9mm.
Attached proposed layout.

 

mews are nice boats. well built. for an extension i would use a good quality construction ply with a couple of coats of epoxy resin rolled on. then you can paint it in a decent exterior paint because the epoxy has sealed it.
as gonzo advised a premade fibreglass shower can save a lot of work. then line the rest of the bathroom in lamipanel provided it is well sealed with epoxy first.
and i can't see why you would need more than 12mm ply.
have you ever been to the maylands boatyard. its quite interesting to walk through there and see how other people have done conversions. freo sailing club quite often has larger cray conversions on the hard too.