Work out if dot & dab or studwork behind my plasterboard?

[raidwi]

I want to secure some brackets to an internal wall hold some heavy things.

I'm looking to get some strong fixings for this (I know which ones I want to get

How do you work out whether it is dot & dab or studwork (with cavities) behind plasterboard on the internal side of an external wall?

 

[RandomGrinch]

Swing a powerful neodymium magnet over the wall, and see if it picks up any screw heads from the studs?

 

[Deleted member 174758]

Get a (rare earth) magnet and run it slowly up and down and across the plasterboard. Studwork will generally be at 400 or 600mm centres from one or other of the corners (it may be in the corners, but overlaps can "hide" the fixings). If you are dealing with PB onto studs a magnet should be able to pick-up either a drywall screws or, in older stud walling, clout nails. Dot and dab will have no metal fixings. It has been used for maybe 25 to 30 years now, so the age of the job can be an indicator, also stud walls aren't normally used for exterior walls, although there are exceptions, such as those walls made with a stud interior wall and a rendered or brick slip-faced blockwork exterior skin. Another way is to take a switch plate off thge wall, if there is one, and maybe remove the back box to see what is behind there

 

[Deleted member 292770]

stud walls generally sound hollow all over when you bang them.
dot and dab will sound more dense and less echoey when you bang it.

 

[foxhole]

Fix one by drilling wall, if it hits a wall then your good to go. If it’s hits stud or fresh air then it may not suit brackets and you will need to rethink.