Finishing balconies - tools and methods

[jack]

Hi all

 

My wife and I have 9 days without the kids coming up first week of the school holidays, and we plan to make as big a dent in the outstanding jobs on the house as possible.

One of those is finishing off balconies. We have three of these: two are about 900mm deep (way less than what "A Pattern Language" says is the minimum for usability!) and run the width of the room they're accessed from (roughly 7m and 4m long).

 

At the moment, they're open joists. These were built up to to a certain height, but with one thing and another this ended up being too high, so we removed the top layer of the frame and now plan to reinstate slightly lower and with a fall.

 

To do this, I need to build a frame from 6x2s, with a slight fall towards a drain along the long length of the balcony. It looks something like this (not to scale!):

 

The original frame that's being replaced was engineered and designed to take the loads from the glass balustrade, and was solely held to together and to the frame below using ring shank nails. Naturally I want to be sure I don't end up with something weaker than the original design and structure. 

 

I could hire/borrow/buy a gas nailer and just replicate what was on offer. Is this the best way to go?

 

The alternative is to use lag bolts and/or lots of smaller (but still substantial) stainless or galvanised screws, along with stainless angle brackets and plates, to hold the main frame together. This will take a lot longer, but I've never used a gas nailer before so am a little nervous about cocking up (plus some of the tales of nailer injuries some of the people we had on site exchanged isn't exactly encouraging!)

 

The OSB on the top will add more strength than was originally engineered (at one point the idea was to have decking that just let water through), so that helps, as will the GRP going on top of the  OSB.

 

Any advice/tips/warnings?

 

Thanks as always.

 

[Jeremy Harris]

I'd be inclined to use bolts to hold the new frame to the old, if it were me.  Might be slower, but you know where you are with bolts and can't easily make an error.  Galvanised should be fine, or even just passivated, as they aren't going to be wet really. 

 

OSB and GRPM sounds ideal, CFS sell kits with all the mouldings needed for the edges etc to make life as easy as possible.  Just need everything to be really, really dry, with no hint of moisture.  If you've not already seen it, CFS have a lot of useful instructional stuff on doing this, too.  I'll declare an interest - my cousin used to work for CFS for a number of years, so I've got into the habit of using them.

[Mr Punter]

I am with the 900mm being too small to be of any use.  1500mm depth means you can have a table and enough room to get round one side.  Can you make it deeper?  I assume this is supported on posts and they are properly detailed at the base so they don't rot?

 

You will need an outlet and downpipe for the drain.  Will the drain channel have a built-in fall?

 

What is the plan for the soffit underneath and the finish on the sides?

 

If this is going the be used and is overlooked, consider using obscure glass so you are less exposed.

[Gone West]

10 hours ago, jack said:

One of those is finishing off balconies. We have three of these: two are about 900mm deep (way less than what "A Pattern Language" says is the minimum for usability!) and run the width of the room they're accessed from (roughly 7m and 4m long).

 

900mm deep is fine depending on what you want to use it for. You won't be able to have a dining table out there but we just stand on ours leaning on the rail and watch the world go by. You get a completely different view standing outside the walls than you do through a Juliet balcony or windows. Finish them and enjoy the summer evenings while they're warm.