Flat roof, rooftop deck?

[TheLiberalLeft]

I'm usually opposed to flat roof property and avoid 2nd level decks above lower level rooms like the plague, but the Mrs has her heart set on an American designed place we've seen on the internet (for a new build).

Has anyone ever seen a house in NZ where the roof doubles as a deck space? Obviously there needs to be a parapet acting as a handrail.

Access to the roof is interesting. It has an outside set of stairs that runs up the side of the building to the roof. This staircase is accessed itself from a ranchslider off a room on the 2nd level, not from the ground, for security. This means of course that the staircase itself sits over a room on the ground floor and this scares the crap out of me in terms of keeping it non-leaky.

I'm assuming the only way this could be done properly is with pre-slab concrete?

[Maccachic]

This is the leak risk matrix prob worth a read: http://www.dbh.govt.nz/UserFiles/Fil...riskmatrix.pdf

[TheLiberalLeft]

Yeah, already commented on your links in that other thread. It's what prompted this OP actually.

I completely understand that what she wants to do is very high risk and I am opposed. I guess what I want to know is if there's a building solution that negates this risk - i.e. solid concrete slab construction. Even then there's still intersections between changes in plane, so the risk can never be eliminated when you have decking over the top of another (lower) room, regardless of whether that deck is a traditional deck, or a roof top.

Was also wondering though if anyone's seen a rooftop deck in NZ.

[Maccachic]

Different link TLL.

There appaears to be some in Tauranga where homes are back from the beach but by adding the rooftop deck they get a "view".

Will check with the surveyors here when they are out of there meeting and see what they have to say.

[TheLiberalLeft]

That's exactly our situation. Back from the beach and wanting to capitalise on a view from the roof.

[Maccachic]

TLL

It can be done you need to make sure the it has:

Fall
Deck Drainage and Outlet
Upstand all the way around the membrane area.
Don't tile directly onto the membrane, have a seperation.

As for the staircase our Architects could always asses it for you.

[Bulldog]

Don't know about NZ but common overseas though in reinforced concrete. I suggest talk to Stresscrete. Ask for one of their Engineers, say you want some technical info. Better to get this sort of info first hand. Most of the blokes (& gals!) in the building/engineering industry are pretty good people, happy to share their knowledge.

I am thinking about using a flat precast panel (we used to call them Unispan) with an insitu topping. Cracking is the big problem but if you don't get you chippy mate to do it, get a proper concretor who does commercial buildings. Failing that, Fletchers make a product Dimond something that worked on the same principle.

http://www.dimond.co.nz/Commercial-Steel-Flooring/Flatdeck-1149.htm

http://www.stresscrete.co.nz/defalt.html

[Buildology]

We deal with a lots of reclads and there are a lot of great waterproofing systems out there.
To lesson the risk we put as much fall as possible,open handrails and sit wooden decks on top that are screwed so you can access the membrane if needed.(not screwed through the membrane)
It's like anything if you do it properly you won't have any problems.
Allan

[Meehole]

Man up and tell her no it's not advisable. Jeez you men can be a pushover sometimes!

[speights boy]

Nah.
Stop being a cheapskate and buy beachfront.

[mrsaneperson]

I have a property that has a flat concrete deck forming a roof over a bedroom . The concrete over the years in one small area had formed tiny fissures where water was seeping in to the room below. The solution i used to fix it was to tile over the whole deck . No more leaks as of now, that was 3 years ago. Any balustrading you do is best to clamp to the sides of the deck rather than afix directly to the flat area of the deck.

[Wayne]

If the view from lower down is restricted because of something infront just buy that something and knock it down.

[TheLiberalLeft]

$800k section in the far north, with coastal pohutukawa. Sure, I'll take a brace. And throw in some bottles of Roundup while you're at it.

[Meehole]

We deal with a lots of reclads and there are a lot of great waterproofing systems out there.
To lesson the risk we put as much fall as possible,open handrails and sit wooden decks on top that are screwed so you can access the membrane if needed.(not screwed through the membrane)
It's like anything if you do it properly you won't have any problems.
Allan

Therein lies the answer, "we deal with lots of reclads".

[Davo36]

Any balustrading you do is best to clamp to the sides of the deck rather than afix directly to the flat area of the deck.

You have to do this now, you can't put exterior balustrading on top of a deck or wall or what have you. This was a big source of leaks I think. Water would run down the balustrading and into the screw holes securing it, and into the structure.

So now it has to be fixed on the sides, it's in the building code.