Fixing a rim joist / wall plate

[wozza]

Hi All,

 

I want to fit a mezzanine floor in my garage. 

 

What are the best fixing to use to fix the rim joist?  How many to use? Fix along the top and the bottom or the middle?

 

The one wall is the existing house wall, London brick and strong mortar, the other wall is new and built with Fibolite blocks. Probably going with 400mm centres so the floor is solid.

 

I have considered either 100mm or 120mm M8 coach bolts with washers and plugs, - the rim joist will most likely be either 6 x 2 or 8 x 2.

 

Any thoughts or suggestions welcomed

 

Thanks, Wozza.

 

 

[Russell griffiths]

I prefer chem fix resin and a threaded stud, that way if the brickwork is a bit suspect or your drill opens up the hole a bit big the resin always fills up the hole. 

 

Spacing would depend on the load it is taking, is it just for storage. 

[PeterW]

6x2 I would use resin studs at 600mm centres spaced alternate 50mm from the top and bottom of the beam and use top hung hangers. 
 

Resin is much better as @Russell griffiths says as it fills the holes. Put them in - drill 3/4 way through the blocks - and don’t be tempted to nip them up til the next day. 

[wozza]

Floor is for storage - but the missus will certainly load it up, the width will be either 2.4 or 3.6 meters so chipboard fits easily, the span will be 3.7 meters.

 

So if using resin studs, how do you go about drilling them to get them accurate or do you do it all at once?

 

Would you do it like this?

 

Fix rim joist with a couple of screws and plugs just to get it level and hold it in place.

Drill through joist and into brick / block - I assume that you do not want to go all of the way through the brick / block?

Squirt in resin and screw in the studs.

Wait 24 hours and then tighten nuts?

 

Do you mean the pre bend type masonry hangers or the ones that you fold over?

 

Thanks, Wozza.

[PeterW]

Couple of bits of scrap timber screwed and plugged to the wall, rest the pre-drilled beam on them and level. 
 

Drill through the holes with a bit with a marker tag on it, inject the resin, tap the stud in and twist it to get a good bond. Washer and nut and do the next one. 
 

Use the stronger hangers with a pre-bent top and the Locator tags then board over the top.  The long ones need you to wrap them over and you can’t do that with a rim beam. 

[tonyshouse]

Pocket into wall if possible 

[wozza]

 

5 minutes ago, tonyshouse said:

Pocket into wall if possible 

 

Its possible, but a lot more work and not as easy to get level? the old wall cavity is between 50 and 60mm, the new wall cavity is 100mm, so its possible but tight if I wanted 100mm bearing, would also probably have to cut out the cavity insulation to get the joist on far enough to swing into place.

Edited May 6, 2020 by wozza

[wozza]

Another question.

 

The joists will run across the garage, one of the joists will run along the back wall - would it be a good idea to fix it to the wall?

[Mr Punter]

Do as @PeterW says with the setting out.  You could fit the hangers to the plate first, to save doing it in mid air.

 

With the resin, drill the holes 14-16mm dia and 60mm deep if 100mm blockwork.  Use M12 studding.  Really clean the holes well.  Insert the resin gun to the back and withdraw as you inject.  Insert the stud and wind it in anti clockwise.

 

Make sure your studs do not clash with the joist hangers.

[wozza]

Could anyone point me to a link for the joist hangers, can only seem to find masonry ones.

 

 

54 minutes ago, PeterW said:

 

Use the stronger hangers with a pre-bent top and the Locator tags then board over the top.  The long ones need you to wrap them over and you can’t do that with a rim beam. 

 

[PeterW]

If it’s only storage then these will do it as they take 280kg per bracket Continuous loading 

 

 https://www.metrofixings.co.uk/main/maincat/getCatitem/Light Joist Hangers LUP /1943/0/0/1

 

 

[tonyshouse]

Parallel to wall best to leave a 50mm gap between it and the wall