Simple framing questions

Hi all,
New to the forum so tia for any help. After being quoted 160k for a 6m x 6m second story extension above existing garage we have decided to split up our house to accommodate our daughters family (common practice these days.) I am basically building 3 walls. 2.7 x 3.5m will create a bedroom in existing corner. 4.45m wall will divide the space from rest of house and create a living area for them.House is on a slab with newish vynil floors.I plan on doing a fair bit of it myself and am ok on the tools but just don’t know what to buy. Just after people’s general opinions would be much appreciated.So here are my dumb questions:
1. 70 x 35mm or 90 x 45mm frames
2. F5 or MGP10 or something else. Need to order asap for Xmas install.
3. Anything required under bottom plate timber or use H3? House has had some termite issues with termites coming through bodgy join in slab near where wall will be.
4. Anything wrong with nailing top plate through existing gyprock or expose ceiling joists and nail direct?
5. Buy a cheap framing gun or screw it together rather than hammer and nail?

Cheers for any help.
Paul

I'm taking it that you're not going up but just partitioning an existing space with timber framed plasterboard lining which isn't bearing any structural load, to make new rooms. If so:

1. 70x35 is adequate as it's just holding plasterboard, but I'd go 90x35 or preferably 90x45 purely for greater rigidity. Also 90x anything allows for standard door jambs and sound insulation batts, which might be handy in a shared house.
2. MGP10 is common basic standard. F5 is slightly lower grade.
3. Termite protection. Get advice from someone who knows what will stop termites. H3 won't necessarily stop them. Maybe a physical barrier, but the little b@#$%^ds can get into everything, including chewing up the untreated core of treated timber. If you're really worried about termites, use steel framing. They can't eat that. And in any event get the current termite entry point fixed.
4. As the walls aren't supporting the ceiling, which presumably is already adequately supported before you make partitions under it, there is no need to remove the plasterboard. It might compress if the ceiling drops, in which case your cornice might distort. If you want to avoid that then remove the plasterboard above the top plate so that the ceiling joists bear on the top plate, but make sure you have a stud under each ceiling joist.
5. Nail gun is much quicker than screwing, even with a fairly expensive collated screw gun. I'm not up to date with prices but if you have a compressor an air nailer might be the cheapest option and pack more reliable punch than low end cordless guns. If this is the only time you're likely to use a nail gun, sell it when you're finished. I and lots of other people have done that with various tools.

If non load bearing partition walls the steel stud and track system available from your local plasterboard supplier is a quick and easy DIY option as an alternative to timber

If the roof construction is trusses the internal walls should only be attached to the bottom chord using internal wall brackets. Do NOT hard block between the top plate and bottom chord. Non load-bearing walls - The Guide
If using timber 90 x 35 will provide a much more substantial frame than 70 x 35. IMO 90 x 45 in these circumstances would be overkill. Beardy's suggestion is worth investigating, he is a builder after all. :2tsup:

Hi Guys thanks for the replies. I am going to try get a chippy to come have a look at the first stage of what I am doing which is a simple dividing wall with door. If it’s a couple of grand he can do it save me the hassle. There is 3 year old laminate flooring that is stuck down on some floor leveller where the wall needs to be. It lifts up ok where I tried it. I assume it would be best to cut the laminate where the bottom plate is or if he suggests fixing the bottom plate through the laminate would this be acceptable?
Thanks and all the best for the new year. Paul

Quote:

---

Originally Posted by Pauljm

Hi Guys thanks for the replies. I am going to try get a chippy to come have a look at the first stage of what I am doing which is a simple dividing wall with door. If it’s a couple of grand he can do it save me the hassle. There is 3 year old laminate flooring that is stuck down on some floor leveller where the wall needs to be. It lifts up ok where I tried it. I assume it would be best to cut the laminate where the bottom plate is or if he suggests fixing the bottom plate through the laminate would this be acceptable?
Thanks and all the best for the new year. Paul

---

I wouldn’t be too concerned about the wall aspect itself but the floating floor is designed to be able to move freely for expansion and contraction and fixing the wall through it may give you flooring problems down the track. Best to cut it where the wall plate sits.

Thanks Beardy and Happy new year it’s a lightning show on the Tweed. Just to clarify the laminate is stuck down not floating as such. There is no tongue and groove just stuck down planks. Cheers,
Paul