![repairing lathe and plaster walls repairing lathe and plaster walls](https://i.ytimg.com/vi/WYFvewX8_Zo/maxresdefault.jpg)
So this time, you will have to wait for it to properly dry before sanding and filling in holes with other coats. These two products cure by drying rather than by a chemical reaction. The Instafill can be put on thickly because of its extremely light weight but, if using drywall compound, that must never be put on more than 1/8th of an inch thick or it will crack as it dries. Now, we take either a standard drywall compound or one of the fine non-sagging light weight fillers like Poly-Instafill (not Poly-Filler, which cures hard like the Durabond). Within 90 minutes it will have set hard but it's not at all dry. It is used to fill in as much of the hole as possible, but never leave yourself a sanding job with this stuff. This heavy body base coat must not stick out past the finished wall surface at all. If it wants to sag, you must work the sag out before it sets, or you will be scraping for a long time to get that wall flat. Then you can immediately go back and put on a rather thick layer. You don't want the patch hanging by a prayer you want it well stuck to the surface. You keep on 'working' it until it has thoroughly stuck to the surface, even if it is just a skim coat. Working the wet material onto the surface with a spatula effectively picks up that dust and works it into the mix. That happens because of the dust on the surface that you couldn't get rid of. You will find that as you apply it, some of it just wants to fall off.
![repairing lathe and plaster walls repairing lathe and plaster walls](https://i.pinimg.com/originals/7f/76/d1/7f76d1219692150e8a16b0a9173ee6bb.jpg)
Work a thin coat onto the lathe boards or filler board and into the edge of the plaster hole.
![repairing lathe and plaster walls repairing lathe and plaster walls](http://i.ytimg.com/vi/UrTYFo4LuI0/maxresdefault.jpg)
Hence they're never used as a finishing product but make a very sturdy filler. These products are rough and cure so hard that they're almost impossible to sand. Start with something like Durabond 90 or SheetRock 90 - which cure in 90 minutes through a chemical process, not by drying. THE FIRST DEPTH COAT IS A THICK PLASTER THAT YOU MIXĪ good job will use two different types of plaster: a quick setting heavy body plaster for the base and a smoother easy to sand plaster for the finish. Often neglected, this 'moist plaster to moist wall' rule is a critical step in any drywall or plaster repair.
![repairing lathe and plaster walls repairing lathe and plaster walls](https://empire-s3-production.bobvila.com/articles/wp-content/uploads/2019/02/2015-06-05-09.54.49-lath-and-plaster.jpg)
Spray it several times, if necessary, to end up with a moist but not dripping wet surface. If you apply plaster to a dripping wet area, you will dilute the plaster and that's not good either. When you put wet plaster on a dry surface, the dry part draws the water away from the joint and you don't obtain as good adhesion as when you apply it to a moist surface. We don't want it dripping, but we don't want it dry. Then, we wet the edges of the plaster as well as the wooden lathe and/or filler board with a spray of water. One of my favourite materials for this is pegboard, because the plaster can grip all those little holes. Drywall is usually too thick and we definitely want whatever material we use, to fill the hole, to be less, not equal, to the plaster wall thickness. To lessen the quantity of plaster required you should screw some kind of material onto the lathe. PARTIALLY FILL THE HOLE WITH SHEET MATERIAL The washers and the outline cut will protect the rest of the wall when you start removing the loose material. Then, with a utility knife, cut all the way down to the lathe (wood) to clearly define the edge of the patch. They will crack the paint a little, but you can touch that up when the patch is finished. Like drywall screws, you want the washers just slightly recessed from the surface of the wall so they can be covered with plaster, but they shouldn't break into the old plaster wall. The extra thin spring metal plaster washers can occasionally be found in hardware stores or at and Amazon.ca. Then, using either thin washers and drywall screws, or special 'plaster washers' with holes in them to help hold finishing plaster, secure the wall all around the area you will be cutting out. Start by using a pencil to draw a line around the entire soft area that you want to remove.Tapping on the plaster gently will give an audio indication of what is solidly attached, and what has come loose. To fix a bulge or hole in a lathe and plaster wall, we need to pay special attention to two things: limit the damage as we remove the loose plaster, and make sure the new plaster sticks solidly to the old lathe.