Welcome back, "dsp"! It's been 9 years! Is this still the same place as in your original thread, from 12 years back?
I have a Garage 6m X 2.5M x 2.4m H internally
Construction? How is that built? Materials, thickness, walls, floor, ceiling, doors, windows, etc...
The plan is to use 150mm x 50mm batten with single outer skin of 5/8 plaster board Rockwall then RC + 2 layers of plaster with GG . (Unlike my pics attached). The frame will be approx. 2” from the single brick wall.
. I'm not sure I understand that correctly, but it seems that you are proposing to build a three-leaf wall? If I got that straight, then from outside to inside you would have: Brick - 2" air gap - 5/8 plasterboard - 50 x 150 "battens" (studs?) - resilient channel - 2 layers plasterboard. Is that it? If so, that's a 3-leaf system, with all the associated downside. Is there a reason why you cannot just build it as a 2-leaf?
For the ceiling, I will be building this on top of the frame with 2 layers of board on Hat channel.
Hat channel is not structural. You cannot use it in place of joists. It absolutely cannot handle such a huge load without being attached to joists.
Again filled with rock wall
I think you mean "Rockwool", not rock wall? Rockwool is a trademark for a specific brand of mineral wool insulatio. You can use any brand of mineral wool, or you could also use any brand of fiberglass insulation, as long as it is in the correct density range.
a floating floor is often pointless and can add more resonance in the room
Yep! Very true:
http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173
I might at least put a self-leveling screed down for the walls to sit on...
Based on that, I assume that the current slab is in lousy condition? Cracked? Flaked? Pitted? Stained?
... with rubber underneath
Why? Is that just for sealing the walls to the floor, or are you attempting to float your walls? Floating walls is just as hard as floating floors: lots of math involved! Do you have the characteristics of the rubber, so you can plug them into the equations? DO you know what the Shore hardness is (durometer), and what scale that was measured on? Do you know the numbers for the compressive modulus, static deflection range, compressive stiffness, shear modulus, etc.? What shape factor are you considering? ... lots of work ahead if you want to float your walls...
On the other hand, there's no need to do that at all. You have an isolated concrete slab on grade: The flanking limit is likely somewhere around 70 dB, so it's very improbable that you'd need to float your walls, or your floor.
The door is at the side of the garage and I plan to have a double door
Do you mean "double door" in the sense of two doors, back to back, one in each leaf? Or do you mean doors that meet in the middle in only one leaf?
the external door will be a steel door that I hope to be insulated
Nope. "Insulated steel door" implies "hollow core door". Bad idea: that's a resonant cavity in there. All of your doors should be solid. Nothing hollow.
The part of the Garage at the front (1.5m into the building) I will put a block wall for security and extra STC hopefully.
Not sure I understand that: What do you mean by "part at the front"? Why do you need that block wall there "for security"? Is there no door on that end of the building? Building a concrete block wall implies that it needs support underneath: You will need to get a structural engineer to take a look and tell you if you can do that safely on your existing slab, or if you will need to cut a slice out of the slab and pour a proper footing / foundation for that wall to rest on. That's a LOT of weight in that wall...
I need to find out if i need to fix the walls to the floor
Check your local building code, or better still ask the inspector who will approve your construction at the various stages, but almost certainly you will need to do that legally, and even if it is not a legal requirement, it's a common-sense requirement. There will be vibrations and large pressure changes affecting those walls, not to mention impact from opening and closing doors. All of those can cause walls to "walk". You are not in a major seismic area as far as I can tell (I am!), so that' likley isn't an issue, but you should still anchor your walls firmly to the floor.
if so that means I need to breach the concrete floor and possible a DPC that will allow damp to rise up.
I don't understand: Why would you need to breach the DPC? You say the slab is 4" thick: why do you think you'd need to go all the way through that and out the other side? Your anchor bolts only need to go a couple of inches into the slab. Nowhere near the DPC. So your comment is rather confusing: Please explain why you are concerned about penetrating the DPC?
Is there a solution to this anyone has come across?
Yes! Don't penetrate the DPC!
2. When joing frames together, (each wall and ceiling) is it best to but the shorter walls to the end of the longer walls or maybe use a fence post as a joining member?
Just follow normal framing practices for two walls that meet at right-angles. No special requirements. I'm not sure what you mean by "fence posts" either: fence posts are usually round, but you need rectangular section lumber for your framing. If you have a place where a 2x4 isn't sufficient for whatever reason, then use 2x6, or 4x4, or whatever, as needed. Door headers often need to be 2x6 in structural (load-bearing) walls, for example, and joists might need to be 2x8, or even more (depending on span, spacing, dead load, and live load). But corners are usually built up from ordinary 2x4's.
3. Is using Nails to build the frames normal as I always use screws for this kind of job. In the UK we have screws in everything
Nails are fine, but if you prefer to use screws, and that's the normal way of doing it in the UK, then screws are fine too. It just takes a hell of a lot longer to screw everything together. With a good framing nailer, I can have the entire wall framed and sheathed before you even get your first stud screwed in place! But check your local code to find out what is allowed. If nailing is OK, make sure you use the approved type and length of nail, and the correct schedule. Otherwise your framing inspector could fail you, and you'd need to do it again...
- Stuart -
