joists - fixing to Nudura and blockwork

[Tom]

Hi all - quick question, blockwork internal walls going up now and will in the near future reach mezzanine height, so I need to think about the floor structure for this. Plans indicate 75x200mm joists at 400mm centres. At one end of the joist will be an internal blockwork wall that come up to the height of the floor and stops, the other end will be the exterior Nudura wall. I'm planning on using the same 75x200mm timber to attach to the Nudura wall (insulation taken back and fixed directly to the concrete) and the internal blockwork wall, then hangers nailed to these. Is this right? What fixings should I use to fix the timber to the walls? These things? https://www.toolstation.com/rawlplug-r-lx-zinc-plated-concrete-screw-anchor/p83182

Thanks all

[markc]

I would be using resin anchors (threaded rods bonded into oversize holes in the wall). Concrete screws should be fine as the will be in shear and unlikely to move but well fixed resins will never move.

[JamesP]

26 minutes ago, Tom said:

Hi all - quick question, blockwork internal walls going up now and will in the near future reach mezzanine height, so I need to think about the floor structure for this. Plans indicate 75x200mm joists at 400mm centres. At one end of the joist will be an internal blockwork wall that come up to the height of the floor and stops, the other end will be the exterior Nudura wall. I'm planning on using the same 75x200mm timber to attach to the Nudura wall (insulation taken back and fixed directly to the concrete) and the internal blockwork wall, then hangers nailed to these. Is this right? What fixings should I use to fix the timber to the walls? These things? https://www.toolstation.com/rawlplug-r-lx-zinc-plated-concrete-screw-anchor/p83182

Thanks all

Hi Tom, would you be able to share a drawing or photograph of the above detail.

[Tom]

Thanks both. James, pic below. Green wall on right is Nudura. Joist goes over one block wall and hangs off the other. Timber wall plates in blue. Hope it makes sense!

[Tom]

Another quickie: what would you overlay the joists with? T+G chipboard?

[markc]

3 minutes ago, Tom said:

Another quickie: what would you overlay the joists with? T+G chipboard?

Yes, glued and screwed

[JamesP]

11 minutes ago, Tom said:

Another quickie: what would you overlay the joists with? T+G chipboard?

I used 22mm Caberdek P5 with D4 glue and screws.

[Russell griffiths]

Another one for studs and epoxy resin. 

If you use those concrete anchors you will get the occasional one that won’t grab. With the resin every one will work if you follow the cleaning of the hole instructions. 

M16 studs here, but I am a nutter. 

[Tom]

Gonna go for M12 studs I think as I'm not such a nutter. Just to confirm that the 75x200mm joists are good to use for the wall plates too?

[markc]

3 minutes ago, Tom said:

Gonna go for M12 studs I think as I'm not such a nutter. Just to confirm that the 75x200mm joists are good to use for the wall plates too?

Yes they are more than enough, as are M12 fixings. Space at 600mm ish between the joist locations

[saveasteading]

On 05/10/2022 at 12:25, markc said:

well fixed resins will never move

Agreed. But NB that badly fixed ones will move. I once thought they were idiot proof, then encountered a different level of ignorance. DIY or supervise as follows.

Hole to be just big enough.

Never skimp on the length as the outer 20mm or so does very little.

Hole must be clean

Adhesive must be fully mixed in proportion...with a mixing nozzle discard any single colour emerging at first 

Screw, don't push, the stud into place

If some adhesive doesn't come to the surface, remove and add more glue.

Doesn't work in cold conditions.

 

Nothing more to it than that.

[Tosh]

i used rawlplug r-kem ii and threaded m16 rod cut to length, 18mm drill marked to depth. bristle brush and puffer to clean out the holes and marked the resin nozzle so I had an idea how far to place the nozzle, i also marked the bar as well so when 'turning' it into the hole again knew when to stop. I'd suggest getting a good gun if you do it this way and you've lots to do as it can put a lot of strain on your hands. Not sure if you can zoom in but here's the ones i done, ring beam i think was 10 x 1 3/4.