MF ceiling grid - hanger distance from walls

[Thorfun]

i'm struggling to find definitive answer to how far from the walls the first hanger should be for the MF7s to connect to. most of the information on the web just says "install a 1200mm center grid". but some mention 450mm for the first hanger from the wall and others i hear mention 450mm from EVERY wall should be the first hanger and then 1200mm centers from there.

 

so confusing.

 

i've trawled videos and the whitebook but can't get a definitive answer and some even contradict themselves! e.g. one video says that the hangers should be 450mm from every wall but then the video shows only 450mm from one wall.

 

in the whitebook i see these drawings for standard ceilings

 

which simply show 120mm from each wall for the first hanger. and this video also shows just 1200mm from each wall

 

but this video says the first fixing must be max 450mm from the wall and then at 1200mm centers.

 

anyone help clear this up please?

[crispy_wafer]

my first hangers were about 300mm ish, as I screwed  to joists which were already spaced, then hangers every 600-800mm, mf7 was again about 600-800mm. Odd spacing every now and then to cater for lighting.  Top hat was then at 400 centres.  Sometimes had to adjust or double up again so lights/mvhr/ac/speakers didnt clash.  A handful of my boards I’ve trimmed down to fit the top hat spacing too.

 

So 300, and about 600 from the wall. 

[joe90]

Having never done or been involved with this kind of kit, does it matter? 🤷‍♂️, as long as there is enough (not too far apart to create sag).I do have a reputation to over engineer stuff.

[Pocster]

Though my ceiling system isn’t the same it’s similar . I just chucked one down the centre of the room and then did the required distance from that to the next run . Distance from wall didn’t care ; no sagging etc is all I cared about .

[Nick Laslett]

I followed the Siniat GTEC materials. Page 22. 

 

https://media.siniat.co.uk/pi48603/original/-1830867374/siniat-drywall-manual-s5-floorsandceilings-v1.0.1_wm.pdf
 

The reason for the different measurements, is that it depends on the overall weight of the ceiling. 

[nod]

For single board The first hanger can be 800 from the wall if you can get a reasonable fixing in the perimeter track Then you need to make a 1200 grid up with your hangers 

D board 600 from the wall and make up an 800 grid 

[Thorfun]

thanks all. was measuring it up and I'm kind of limited by the beams and not wanting to fix too close to the edge of a block! so after a long think I'm going to fix in to the first block from the wall (approx 300mm) and then every second block which equates to approx 1000mm centres along each primary. 

 

it's a similar story for the distance between each primary in that I don't want to fix too close to the edge of a block and so I'm going to see what distance works best. it'll probably be a bit all over the place but hopefully will be a mixture of either 600mm or 900mm centres if I can make that work and will be more effort having to cut the insulation to size rather than just slotting it in but, like @joe90 says, as long as I don't exceed the maximum centre distance then I can fix as often as I like, right? the more the better for strength it just costs more and takes more time.

 

my issue now is I bought these https://www.toolstation.com/dewalt-tapper-pro-blue-hex-head-self-tapping-screws/p86871 as @nod said the blue tex screws are best for fixing the hangers but the box says to use a 4.8mm drill bit! ffs. I have a 5mm drill bit and it's now too late on Christmas Eve to get a 4.8mm bit. if I can't fit the ceiling I'm going to have to spend time with the family over Christmas instead.

Edited Tuesday at 17:05 by Thorfun

[Thorfun]

**** it. everything I can find online says for 6.3mm concrete screws to use a 5mm drill bit. I'm sure it'll be fine. 

[crispy_wafer]

👍 for the plan of attack, 🤣 for having to spend time with the family

[joe90]

4 minutes ago, Thorfun said:

**** it. everything I can find online says for 6.3mm concrete screws to use a 5mm drill bit. I'm sure it'll be fine. 

Try one and see 🤷‍♂️

 

if I can't fit the ceiling I'm going to have to spend time with the family over Christmas instead.
 

your leaving it a bit late 

[Thorfun]

Just now, joe90 said:

Try one and see 🤷‍♂️

 

if I can't fit the ceiling I'm going to have to spend time with the family over Christmas instead.
 

your leaving it a bit late 

sadly the day job keeps getting in the way of the self-building and I've used all my holiday allocation up this year on the house so the only time I have left to work on the house is weekends and public holidays. 

[Pocster]

26 minutes ago, Thorfun said:

sadly the day job keeps getting in the way of the self-building and I've used all my holiday allocation up this year on the house so the only time I have left to work on the house is weekends and public holidays. 

Do this Xmas day - SWMBO will love it 🙄

[nod]

50 minutes ago, Thorfun said:

thanks all. was measuring it up and I'm kind of limited by the beams and not wanting to fix too close to the edge of a block! so after a long think I'm going to fix in to the first block from the wall (approx 300mm) and then every second block which equates to approx 1000mm centres along each primary. 

 

it's a similar story for the distance between each primary in that I don't want to fix too close to the edge of a block and so I'm going to see what distance works best. it'll probably be a bit all over the place but hopefully will be a mixture of either 600mm or 900mm centres if I can make that work and will be more effort having to cut the insulation to size rather than just slotting it in but, like @joe90 says, as long as I don't exceed the maximum centre distance then I can fix as often as I like, right? the more the better for strength it just costs more and takes more time.

 

my issue now is I bought these https://www.toolstation.com/dewalt-tapper-pro-blue-hex-head-self-tapping-screws/p86871 as @nod said the blue tex screws are best for fixing the hangers but the box says to use a 4.8mm drill bit! ffs. I have a 5mm drill bit and it's now too late on Christmas Eve to get a 4.8mm bit. if I can't fit the ceiling I'm going to have to spend time with the family over Christmas instead.

I’ve been doing this for forty years 

Trust me 

[Thorfun]

4 hours ago, nod said:

I’ve been doing this for forty years 

Trust me 

What size drill bit would you use for 6.3mm Tek screws in to concrete blocks? 😊

[nod]

52 minutes ago, Thorfun said:

What size drill bit would you use for 6.3mm Tek screws in to concrete blocks? 😊

I buy 100s boxes of different type fixing screws each year 

The blues ideal for fixing to concrete 

[Thorfun]

10 hours ago, nod said:

I buy 100s boxes of different type fixing screws each year 

The blues ideal for fixing to concrete 

yes! but what size drill bit do you use for those 6.3 x 32mm blue Tek screws?

 

the DeWalt ones I bought say 4.8mm drill bit on the box but other makes on the web say 5mm.

[saveasteading]

It will say on the package and needs to be exactly right.

It's worth getting a new, big brand, bit.

[Thorfun]

2 hours ago, saveasteading said:

It will say on the package and needs to be exactly right.

It's worth getting a new, big brand, bit.

well, I have some concrete screws that do not say on the packaging what drill bit size to use. and research on the web seems to suggest that it depends on the material being screwed in to. 

[saveasteading]

These are specifically for concrere I hope. If so, then I'm sorry but there is something dodgy about structural fixings without instructions.

These are hitech products and will have precise requirements.

Too big a hole and they won't grip...expensive collapse?

Too small and they won't fit and may damage the thread.

Perhaps buy some new ones.

[joe90]

3 hours ago, saveasteading said:

Perhaps buy some new ones.

Yes, Too important to get wrong. I bought some last year for a job and the drill size was specified on the box. @nod will tell you the best ones to get 👍

 

(back to my mince pie and cream 🎄)

[nod]

19 minutes ago, joe90 said:

Yes, Too important to get wrong. I bought some last year for a job and the drill size was specified on the box. @nod will tell you the best ones to get 👍

 

(back to my mince pie and cream 🎄)

It really does depend on the surface 

Hard concrete can be fine with a 6 But softer surfaces can be 5.5 or even 5 

The trick is when you are screwing them in They shouldn’t blast in in one or slow the dril They should just go in steady 

[joe90]

8 minutes ago, nod said:

t really does depend on the surface 

I am the same with red rawlplugs 5.5 in softer stuff and 6 in hard stuff. Try 5.5 fir one and see how it goes, if too tight then  use 6mm .

[Pocster]

I know the exact drill size required .

But I’ve got turkey and wine to consume .

[Pocster]

5 minutes ago, Pocster said:

I know the exact drill size required .

But I’ve got turkey and wine to consume .

@Thorfun let it go for today - no rush …

[crispy_wafer]

can recommend the the blue bosch expert drill bits, brilliant! saves having to climb up and down ladders to fetch or carry 2 drills, especially when metal and masonry is involved.