Weird joist. Will floor joist take the weight

[Cwurly]

Hi,

My First question here.

I'm currently renovating a ground floor 1950s ex-council maisonette. And I am wanting to lower existing ceiling 100mm, insert 90mm acoustic insulation, attach resilient bars and overboard with 15mm Soundbloc board

My question is will the joist take around 100Kg of plasterboard - albeit evenly distributed.

I have a room with joist span of 2.7M the joist height is 7" and this is where it gets weird, the timber width is only 1.5" top and bottom, in the middle is a steel construct of 'W' shapes the whole length. I do hVe pictures and I'm currently trying to upload.

Has anyone come accross these before, and will they take the added weight of the plasterboard.

Many thanks[/list]

 

[Cwurly]

Untitled

• Cwurly
• 3 Mar 2014
• 1

I hope this is self explanatory. The black is metal and at the top is what looks like 2x2 and same at bottom of joist. At the bottom of the photo you can see existing plasterboard screwed to it.

 

[tony1851]

They're not wierd, just steel lattice joists common after the War when timber was in short supply.
100kg of pasterboard distributed over - say - 11 or 12 sq.m. is nothing to worry about.

 

[Cwurly]

Thanks for the reply. No I suppose weird is an incorrect term. I meant weird to me as I have never come accross this type before.
Appreciate the reply - thank you