Lowered ceiling, simplest option?

[Jolo]

Now that my MVHR saga is finally over, I'm ready to box in the ductwork. Luckily I was able to route the ducts with minimal damage in the rooms themselves, as upstairs we had big enough ceiling voids, and downstairs all rooms connect off the hallway.

But this does meain that the hallway has taken the brunt of the routing -- see photo!

Now as this ceiling is pretty high (2m 60cm) I'm not worried about dropping it 15cm or so. It's also an opportunity to add better lighting (currently the only light is towards the back, it really needs one at both ends, or even three).

The wall on the left side is wood, and the right side is brick (it's a load-bearing wall), but the ceiling is a bit of a mystery to me. It's either concrete or it might be a reinforced brick floor (1960s Dutch "Nehobo" floor, like a wall made of hollow bricks, with steel bars for strength, laid on its side). But whatever it is, it's a real pain to drill into. I've managed it here and there, but I've also managed to break at least two drill bits in the process! 

So ideally I'd like to get away with no (or minimal) drilling into the ceiling, if it can be avoided. Though if I have to, it's possible.

However the hallway is only 1 metre wide, so my question is, do I even need to drill into the ceiling? If I put wooden battens along each side wall, then cross-battens across the span, will that suffice to hold a single-layer plasterboard ceiling? Or is a metal frame the better/easier option? Or do I really need some sort of support along the middle to prevent sagging?

Thanks in advance!

Edited 6 hours ago by Jolo

[ProDave]

As it's only supporting plasterboard I would construct a false ceiling using 38mm by 89mm CLS timber supported just from the walls with a similar sized CLS fixed to both walls.  That then gives you plenty of room to accommodate the wiring for the lighting changes.

 

You could probably so it in a thinner size using metal framing, but someone else would have to advise on that, I have not used it.

[Redbeard]

I think we need a pic of the other end (the end nearest the camera position, where the stairs open up and there is no wall on the L). Likely no problem spanning from wall to wall in the 'distance' of this photo (where the coats are), but then nearer the camera you only have one wall... Is there a 'stub' of wall behind the camera on the LHS so you can bridge across the stair opening?

Edited 6 hours ago by Redbeard
added bracket

[Jolo]

Thanks both for your replies! Very helpful.

 

And well spotted, there is a gap in the wall where the stairs are, but there will be some pieces of wood coming down there in line with the wall, as the ducts run down the wall above the stairs and will need boxing in too. So my plan is to have some vertical battens beside the ducts. And at the end, connect above the front door.

 

I've taken some more photos, if that helps clear things up!

[ProDave]

So you also need to box in the bit up the stairwell where the pipes go up, but only that bit otherwise you will narrow the stairwell.  Up to where the newel post would be my suggestion.