Ok so i know there are alot of posts asking this but my situation is special. We have a house that was built around 1915 it was a old farm house outside of town and in 1950 they moved it into town most of it is still old plaster and lath but the exterior walls are insulated with what looks like blown in insulation it is a 2 story home as well.I am starting upstrairs since we are living in the bottom story.The attic is insulated with blown in insulation and the exterior walls are as well.
I am seeking advice as to what to do we want to take the plaster down and drywall it so i can rewire it as well with a new updated breaker box and breakers currently our 5 bedroom 2 bath home is wired off 3 breakers.For the sake of saving money we are considering leaving the lath up to keep the insulation in the walls and in the attic would this sound like a good idea to you?Also i was reading some other posts of peoples ideas and someone mentioned leaving the lath and puting 1x2 over the studs and puting 3/4 rigid foam between them then puting up drywall for extra insulation.The plaster is in fairly bad shape 1 room for sure has to be gutted of the plaster due to water damage making it fall the studs are not damaged though.So any ideas and advice would it hurt to do the foam or to leave the lath?

 

Are you completely retrimming everything? Door trim, baseboard, window trim, etc?

 

I could retrim it has 1x6 for baseboards right now and the doors are trimed in 1x4 i was planing to just clean the old trim up and repaint and reuse it.I did consider i would have to rework the window trim a bit if i put the foam board under the drywall over the lath

 

Yes, you'd need to jamb extend all your windows and doors, then retrim everything because of the added thickness of the 1x2 and drywall, not to mention all your outlets and switches would need to be moved out 1 1/4" or so. It will create some problems with the door latches (extended strike plates will be needed so that the latch doesn't rub on the new extension jambs) or you could install new doors while you're at it.

Personally, i'd probably not go to all the work of 1x2 and foam because it adds so much work for very little value. I'd leave the lathe and then use either 3/8" or 1/2" drywall over the lathe so that you wouldn't have to add any extension jambs to anything. You might not even have to replace the baseboard or trim if you go that route.

 

I think you are right the foam would be alot of work and not add much since the exterior walls are insulated already.Also i did not think about the doors.The windows would be easy to fix should i decide to add foam if i do it will only be to the outside walls and the ceiling since you dont loose heat through interior walls and the doors are all on interior.I will pull the trim off the door tomarrow and see what will work best 3/8 or 1/2 to try to make it match to the thickness of the current plaster.Also on the elect boxes i am rewiring and puting new breaker box in.I am going to wire each room on the 3 interior walls since the exterior wall has insulation.Each room has 3 interior walls and 1 exterior wall. 4 rooms on the top story.I really hate to half ass it but any thoughs about puting drywall over plaster? The only reason i can find that really worries me is the added weight to the walls

 

Are you going to install the drywall directly over the plaster or just the lath?
Plaster gets laminated with drywall all the time. The main thing is to use screws long enough to secure the drywall to the framing. The lath isn't a suitable place to screw the drywall to.

btw - welcome to the forums!

 

Before you decide to leave the insulation and lathe, I would inspect the insulation to ensure it's still in good condition. As long as you're doing all this work, I'd hate to have less-than-adequate insulation in it. Depending on how old the insulation is, it tends to get compressed and less functional over time.

 

You will have the same scenario if you put the new drywall over the plaster. You would either need to flat tape right up to your existing trim (then it will appear recessed) or you will need to remove all the trim, extend all doors and windows, replace baseboard and face trim, extend outlets, etc.

Going over the lathe can be a pain in the butt but I think in this case its probably worth it to leave the lathe and go over it. The biggest pain when you do that is the plaster stuck BETWEEN the lathe because no matter how good of a job you do removing the plaster there are always a few pieces of plaster here and there that are sticking down between the lathe and that can create a bump under the drywall. So you need to scrape and check the lathe carefully before you put up each sheet.

It's easy to inspect the insulation through the lathe as Zorfdt said. And I agree with Marksr that you will need to secure the drywall to the studs, not just the lathe. 1 5/8" screws are usually long enough. You will probably also need to check the wall with a straightedge to ensure the studs and lathe are straight enough for drywall. You may need to add a shim here or there before you put up the sheetrock.

 

It is very difficult to remove the plaster without taking some of the lath off too or bending or breaking it. You would end up with a very crooked, wavy surface to try to put drywall on. Also you will lose some insulation in the process.

Maybe you are thinking it will be less mess to leave the lath and insulation. You are right but if you take it all off and put in new insulation you will have a better insulation job. You are already aware of the accompanying problems of taking off all the lath and plaster and making things fit again. Consider this Two layers of drywall -- probably 3/8 and 1/2" will come closest to fitting what you have.

Often the plaster is thinner on a second story than on the first. It all had to get up there the hard way and the plasterers' laborers did not want to carry it up there so the plasterers layed it tighter. Therefore the dimensions might be different on the different floors.
Maybe 5/8 rock and drywall shims will make things fit.

 

sound the alarm tightcoat you are 100% correct about the plaster it is very thin upstriars i would say its less then 3/8 thick.After looking over the windows and the lath size i think you all are right i will have to take the lath off as well and 1/2 drywall should be a perfect fit.Now for the insulation news it has not all settled down but for some reason there are gaps in it.The house has old wood siding and i can see light through the lath in the gaps of insulation.So its looking like i will have to gut the plaster and lath atleast on the walls and rock it all in 1/2 and put new insulation in the exterior walls.Question though can i caulk the gaps were i can see light from before i insulate the wall?I would love to have someone do spray foam but funds are not allowing that right now

 

Any voids you see in the exterior wall should be able to be caulked before you insulate. This will also be a good time to inspect your electrical, maybe add an outlet or two if needed. You will also want to double check your stud spacing. Since they weren't using standard size materials [4',8',12'] they didn't always worry about getting the studs on 16" or 24" centers.

 

I checked the stud spacing earlier its on 16in centers.We planed to rewire the entire house well doing this so each room can be up to code and on its own breaker.Currently the entire house is wired on 3 breakers and no 220 so we had to go with NG dryer.They wired the top story via the attic and the bottom story from the tiny space under the house lol.I was planing to only wire the interior walls but now with having to do new insulation i can do the exterior walls to.I am considering saving the ceiling insulation though and leaving the lath on the ceiling and just puting drywall over it.That i know is insulated good i have been in the attic already and checked it.It has no trim around the top of the room so it would not be a sizeing issue

 

On another issue i had planed to put a new load center/breaker box in since the current is old as dirt and only had 4 spots.My question is what size do i need lol.the house is a total of 5 bedrooms/2 bathrooms/laundry room/dining room/living room/kitchen i also do plan to have a Dishwasher and we have a massive deepfreeze that probably could use its own breaker any ideas.Also i know you can buy the slim breakers that give you 2 breakers in 1 slot any thoughs on them? i hae used them in a garage before used a 2 space box and got 4 circuits

 

You might do better posting that question in the electrical section. I do know it's better to have too big of a box [allowing for future expansion] than one that is just big enough. I'm not an electrician but my thoughts on the skinny breakers is it better to plan for box big enough to accommodate the full size breakers. That said, my breaker box that is original to the house has those slim 1/2 size breakers although I don't know why - there is room enough to replace them all with full size breakers.

 

Sorry your right i should have posted that in electrical section was just something that poped in my head to ask.I looking at some that lowes carries and its going to suck mine is in the kitchen atm and the 30 slot boxes are huge lol like 14inx39in

 

Usually, but not always you can install new drywall right over the existing plaster with long enough screws. Usually but not always the only thing you will have to adjust is the electrical boxes. This would be a lot less mess than taking off the plaster and trying to leave the lath.

 

You can install a 1x2 frame around the breaker box and then a cabinet door to match or compliment your kitchen cabinets. This is done all the time to hide breaker boxes

 

My post # 16 above is in response to part of post # 12 above with reference to leaving the lath on the ceiling and rocking over it. I am saying that on ceilings usually but not always all that one has to contend with is extending the electric boxes when he rocks right over the plaster. Long enough screws are very important and must hit the joists not merely the lath.
Lath 3/8" + plaster about 1/2" + new drywall 1/2" + penetration into the stud 1" = screws 3 1/4 or 3 1/2". Some people ask about adhesive. . My thought is that the adhesive is only as good as the paint on the plaster. It can't hurt and might help but in the long term is no substitute for enough screws.

 

If you're not putting in central A/C, then a 100A service should be plenty for you. In our old Queen Anne I put the big main panel for the new 200A service in the basement and fed a small subpanel on each floor from that.

I rewired that house from service entrance to ridge, adding more than 50 receptacles in the process, plus 30-odd switches and some ceiling boxes. The only plaster I removed was plaster that had failed - none for wiring (120 or phone or data or coax or security - all added) nor plumbing. It can be done.

The failed plaster was replaced with drywall shimmed out so that the face of it was where the face of the plaster was before - flush with the casings. The trim went right back on, no hassle.

 

Ya its looking like i might leave the plaster idk we are tring to decide atm.We have done 1 room so far taken all the plaster out and lath but have left the ceiling lath up to keep the insulation.We took the insulation out of the exterior wall and its got so many gaps between the 1x6.Its very annoying we really want to gut all the exterior walls because i am sure they all got the gaps between the 1x6's but i am not so sure now.I am wondering if i should just leave the plaster up and only damage what i need to rewire it/Fix any currently falling plaster.We did want to have CH&A at one point and that is why we are still thinking about removing and rocking everything.Drywall is so much easier to work with in the end then plaster