Roof ‘windows’

[uncle nick]

Hi all, while working on our project narrowboat, we’ve found the three circular ‘patches’ on the roof (two 10” dia and one 8” dia) are actually Perspex that’s been painted over. Inside was boarded as if they weren’t there, apart from the fact they leak, which rather gave the game away. 
Can anyone recommend some sort of porthole type fitting that would look good, not hold water or leak and not be a snag hazard for the centre line?

The only things I’ve managed to find so far are the yacht type hatch covers (which I’m not sure would look right) or the bull’s eye type (which are smaller, potentially a fire risk and very expensive). 
Or, although we like the idea of the extra light, would it be be better to just have them properly welded up flush?

Thanks. 

[LadyG]

Why not fit a standard porthole window bearing in mind they are not designed for standing on. This might create condensation, but would be cheaper than a hatch. Or just repair the roof, I think that would be more sensible. 

 

If you have a white deckhead and keep the other paint colours light you won't need roof lights in most boats.

Edited November 2, 2024 by LadyG

[SteveLevis]

I would get them welded up. We had 2 roof lights on our last boat and they leaked....

[Stroudwater1]

Bulls eyes are great at letting light in. A small circle of sanded Perspex in the centre attached with a wide of silicon or a daub of paint in the middle would stop any fire risk. 

 

Any hole in the roof can leak, Captain Tolleys creaping crack cure can seal small ones. 
 

It looks like the holes were once Bulls eyes. Appreciate they are costly but they are well worth it. 

[GUMPY]

Just get some 3mm steel panels welded to cover them. It's what I did when I removed a stove at the rear of the boat. Bottom left of the picture.

 

 

[NB Alnwick]

9 minutes ago, GUMPY said:

Just get some 3mm steel panels welded to cover them. It's what I did when I removed a stove at the rear of the boat. Bottom left of the picture.

 

Best plan! Keep it simple!

[uncle nick]

1 hour ago, GUMPY said:

Just get some 3mm steel panels welded to cover them. It's what I did when I removed a stove at the rear of the boat. Bottom left of the picture.

 

 

Thanks to all for the replies. 
We thought the panels were welded on steel until I started to remove the ceiling cladding. That’s a great pic!

[magnetman]

It is possible these were added when the Boat was moored in a location with unsatisfactory light from the sides. Under trees or near tall buildings for example. Get more light by adding holes in the top of the cabin. 

 

Block them with pieces of wood and if your use of the vessel means you can tolerate the reduction of light from above then the answer is, as already indicated, to get 3mm steel discs welded over the holes.

 

It is a good time of the year to experiment with daylight. 

 

 

 

 

[uncle nick]

7 minutes ago, magnetman said:

It is possible these were added when the Boat was moored in a location with unsatisfactory light from the sides. Under trees or near tall buildings for example. Get more light by adding holes in the top of the cabin. 

 

Block them with pieces of wood and if your use of the vessel means you can tolerate the reduction of light from above then the answer is, as already indicated, to get 3mm steel discs welded over the holes.

 

It is a good time of the year to experiment with daylight. 

 

 

 

 

Interior light isn’t too bad, or hasn’t been so far. It was still ok working inside yesterday at 4pm without artificial light, and that’s with them (badly) painted over and partially blocked by cladding. 
Plating over does seem the sensible option. 

[David Mack]

8" and 10" sounds big for a roof bullseye - they are normally 5-6" diameter.

Perspex flush with the roof also sounds like a hazard for anyone who might step on them. I would expect toughened or laminated glass of suitable thickness to be safe.

For roof lighting, most narrow boats use a pigeon box, or it's larger dog box cousin, or a houdini type hatch. Condensation and dripping can be a problem with all of these.

[uncle nick]

6 minutes ago, David Mack said:

8" and 10" sounds big for a roof bullseye - they are normally 5-6" diameter.

Perspex flush with the roof also sounds like a hazard for anyone who might step on them. I would expect toughened or laminated glass of suitable thickness to be safe.

For roof lighting, most narrow boats use a pigeon box, or it's larger dog box cousin, or a houdini type hatch. Condensation and dripping can be a problem with all of these.

Yes that’s what made us believe the painted circular patches on the roof were steel, until we investigated properly. 
I suppose a reducer could be welded on to allow bulls eyes to be fitted but it seems like a lot of bother for a little extra light. 

[jonathanA]

could be an opportunity to fit some extra ventilation (mushrooms/flying saucers) but if you don't need that then i'd agree weld em up.  or even drill tap and bolt some cover plates over. 

[uncle nick]

Just now, jonathanA said:

could be an opportunity to fit some extra ventilation (mushrooms/flying saucers) but if you don't need that then i'd agree weld em up.  or even drill tap and bolt some cover plates over. 

Bolting the plates on would leave the option to easily change to something else in future, good shout, I hadn’t thought of that option. Thanks 👍

[Covfefe]

We had a roof prism, didn’t increase the light much, but used to drip lots of condensation in the winter.

[magnetman]

Despite the negative press...

 

If the Boat is warm enough and well ventilated prisms or even portholes mounted in the cabin top can work without condensation. 

 

However it is common for there to be inadequate ventilation. A way to help reduce problems is to install the prism or porthole then sikaflex a flanged perspex dome on the outside to create a thermal break. 

 

 

[uncle nick]

6 hours ago, Covfefe said:

We had a roof prism, didn’t increase the light much, but used to drip lots of condensation in the winter.

I’m not sure exactly what a roof prism is, I’ll have to have a Google. Not sure a little extra light would be worth more drafts or condensation. 

6 hours ago, magnetman said:

Despite the negative press...

 

If the Boat is warm enough and well ventilated prisms or even portholes mounted in the cabin top can work without condensation. 

 

However it is common for there to be inadequate ventilation. A way to help reduce problems is to install the prism or porthole then sikaflex a flanged perspex dome on the outside to create a thermal break. 

 

 

Not heard of, or seen, a flanged Perspex done either but I can guess it would reduce the temperature difference, and so reduce condensation but also possible reduce any extra light. 
 

We were talking to a lady earlier who lived aboard 100%. She had reservations after adding a duck hatch to her boat, just another source of drafts and leaks was her opinion. So openings in the roof could be even more trouble. 
Plus we can’t find anything to fit the 8” and 10” openings that isn’t a trip / head banging hazard or looks likes it was stolen from a passing yacht! 🙄

[ditchcrawler]

14 hours ago, uncle nick said:

I’m not sure exactly what a roof prism is, I’ll have to have a Google. Not sure a little extra light would be worth more drafts 

No drafts its fully sealed just like a bullseye Davey and Co. Deck Prism/Light Rabetted | Captain Watts Chandlery

 

 

[uncle nick]

6 hours ago, ditchcrawler said:

No drafts its fully sealed just like a bullseye Davey and Co. Deck Prism/Light Rabetted | Captain Watts Chandlery

 

 

Thanks for that. I’m guessing it points upwards?

It’s definitely looking like I’m going to need a plate to cover the existing holes, then find something to fit into the new plates. 

[magnetman]

20 hours ago, uncle nick said:

 

Not heard of, or seen, a flanged Perspex done either but I can guess it would reduce the temperature difference, and so reduce condensation but also possible reduce any extra light. 
 

 

[uncle nick]

Thanks for the link. 
I’m not sure how that would look on a narrowboat. That’s what I meant by yacht fittings, though that is clearly disrespectful to yachties! 🙄

[Covfefe]

6 hours ago, ditchcrawler said:

No drafts its fully sealed just like a bullseye Davey and Co. Deck Prism/Light Rabetted | Captain Watts Chandlery

 

 

This looks very much like what I had, and there was no thermal break so it’s used to suffer from lots of condensation in winter.

[uncle nick]

Sadly I’ve more or less given up on the idea of looking up at the stars / clouds and starting to agree with the mrs that it’ll be more bother than it’s worth. 
The prospect of leaks and condensation means plating and welding up the holes makes more sense. 
Thanks to all for your input. 👍

Edited January 10 by uncle nick

[Alan de Enfield]

57 minutes ago, uncle nick said:

Thanks for the link. 
I’m not sure how that would look on a narrowboat. That’s what I meant by yacht fittings, though that is clearly disrespectful to yachties! 🙄

 

How about Lancaster navigators. 

One of these was in the top of the Lancaster above the Navigators seat so he could take star shots to confirm location, here is one that was sold at auction (not including the clock)

 

 

 

Called an Astro Dome

 

 

Edited January 10 by Alan de Enfield

[uncle nick]

Thanks Alan. 
A Lancaster bomber can make anything look cool, I’m not so sure how it would look on a 1980s tatty narrowboat! 😀

[magnetman]

I like having astro domes on the Boat. Handy for checking the weather in the morning. 

 

So much better than portholes ! or scuttles. 

 

 

 

Whats it like out there? A bit chilly? maybe a spot of sunshine? 

 

Lets have a look out of the astro dome. 

 

 

 

I seem to recall these were used on small blue water sailing Boats..