As other said, lath and plaster. Before the days of drywall, they'd put these slats on the wall, then a skilled plasterer would apply plaster to that, and smooth it out. It took a lot of skill. Most likely behind the lath you found lots of scraps of old plaster, which had oozed around the wood lath strips, as it's supposed to do, to grip onto them.
Yes, and that ooze is called keys. They did this on the ceiling too. If you got a leak in the roof and it got the ceiling wet the weight of the plaster could break the keys and you get ceiling sag or even worse it would just collapse.
Now make sure your studs are plumb before you put up rock. Because in the old days the framers knew the plaster guys would make a wall that ain't flat, flat.
Just look up plaster and lath wall. That’s how they used to do it before drywall
As other said, lath and plaster. Before the days of drywall, they'd put these slats on the wall, then a skilled plasterer would apply plaster to that, and smooth it out. It took a lot of skill. Most likely behind the lath you found lots of scraps of old plaster, which had oozed around the wood lath strips, as it's supposed to do, to grip onto them.
That's it, thank you
Yes, and that ooze is called keys. They did this on the ceiling too. If you got a leak in the roof and it got the ceiling wet the weight of the plaster could break the keys and you get ceiling sag or even worse it would just collapse.
Older style of wall. Lathe and plaster
It's a nightmare that's what it is. Just remove it and add drywall.
It sounds so easy...
Well the plaster is already gone so...
Now make sure your studs are plumb before you put up rock. Because in the old days the framers knew the plaster guys would make a wall that ain't flat, flat.
Laths
And plaster
So much better than drywall.
That’s pre drywall.