How do I tell if I have Drywall or Plaster walls?

As the topic states, how do I tell if I have Drywall or Plaster walls?

The walls have a bumpy texture but mostly smooth, there are areas where some bumps though that stick out a bit. I'm not sure if the larger bumps and imperfections are due to horrible painting or what. Nonetheless, I want to smoothen out the wall and fill a few dents and areas where old paint has chipped off and created an uneven surface.

Any tip or suggestions?
Thanks

 

If you take off a switch plate and inspect between the elec box and the wall you should be able to tell. Older homes will have wooden lath and then plaster, newer homes will have a plaster veneer over drywall. Drywall alone will just have paint over the drywall - you won't see much build up over the drywall.

It probably doesn't matter too much if it's drywall or plaster. You can do some smoothing by scraping and sanding but if that doesn't get it good enough, it would be best to skim coat over the wall [skim coat = thin coat of joint compound over entire wall] If you do this to all the walls, you'll have a nice slick finish. If you only do portions, you'll need to texture those areas to make them match. Just let us know

 

I don't even know if the texture on the wall was intentional, it looks like the results of sloppy painting to be quite honest. It seems almost as if they splashed a paint roller into the paint can and then threw it up on the wall to cover it. Therefore, I think I am going to lightly sand the whole wall, patch a few nail/screw holes, wash it down, then give it a fresh coat of paint.

Comments or suggestions?

Furthermore, will I need to use a primer before painting? It currently has a white latex paint that I will be sanding down a bit and I'll be using a dark grey/blue latex paint to cover it all up.

 

Unfortunately latex paints don't sand very well it heats up and kind of melts - plugging up the sandpaper..... but sanding is a good place to start. Using a putty knife or broad knife to 'shave' off the high spots will do the most good.

More than likely you'll need to apply more j/c than you expect [it will sand easy] so a primer would be in order. If you get it mixed to match [or close] to the finish color, it will make coverage easier.

 

Thanks for the information. I am not one that has much exp with tools in general, let alone fixing up things around the house. This is a huge learning exp for me and I certainly don't expect it to go smoothly. I'll be happy to get it done within a week (or two). lol

Thanks again.

 

your more than welcome

just to clarify, scrape what you can first and then sand.

 

This is embarrassing, and I know it doesn't really matter much at this point but I'd like to know for future reference. After taking a faceplate off, what am I looking for to tell what type of wall I have? Are there any comparison images showing the side of drywall vs the side of a plaster wall?

It may be obvious to an experienced eye but for me, it's like asking a city boy what plants are edible in the forest...

Thanks again!

 

I'm sure someone smarter than me could find a pic to help you

When you remove the switch plate you'll probably see the edge of a 2x4 on one side of the electrical box. The top, bottom and other side will be open. There is usually enough of a gap between the wall and the box to show what type of wall you have. Plaster walls are thicker than drywall. Drywall is normally 1/2" thick. The gypsum core of drywall is a white/grey color with paper on each side. Plaster will have lath [wood or drywall] and then a layer of plaster between the lath and the paint.

If you need to probe around the exterior of the box to get a better view - remember, electricity runs thru the wires in the box!

 

Unfortunately, the holes are cut very small and the boxes are pretty fit in snugly while being flush with the wall... I'll be turning the breaker off and replacing all of the light switches and outlets in the days to come so I'll then take a peek around the boxes if it's not too much of a hassle.

And as always, thanks again.

 

A good sign of plaster is that there is no gap around the box. The plasterer worked right up to it. You might be able to lift a door casing on the inside of a closet and tell what you have. How old is the house?
Can you get into the attic and move some insulation to see what is there? Wood lath are strips of wood 1 1/4" wide with spaces between that the plaster squeezes into. Gypsum lath looks a lot like drywall only the sheets are 16" wide so if you see joints every 16" then you have gypsum lath and plaster. If the joints are every 48" then you probably have conventional drywall, however it could be veneer plaster.
One other thing: Plaster is a lot harder than drywall. When you scrape it if is sound like you are scraping a rock it is probably plaster.

There is one other idea: You might have plaster that someone put some drywall goop over. If you scrape that off and get to a hard as rock layer then you must have plaster. it could be conventional plaster or veneer plaster.

How old is the house?
If it is more than 75 years old it is probably plaster. If it is 50-75 years old it could be plaster. If less than about 50 years old, with some geographical variances, it is probably drywall.

 

I'm not sure when the house was actually built but the dates on the blueprints say 1958. I know drywall didn't become popular until the 50's but I'm not sure if the builders were on top of the current trends when building this house or if the owners requested it to be plaster...

Anyway, there is a small attic - larger than a crawlspace but not big enough to walk in. Nonetheless, I could probably get up there and take a look when I get a chance...

Thanks again for the detailed information and prompt responses.

 

While in the process of replacing my light switch, I went ahead and took a picture of the wall. I'm not sure if it helps any but can anyone tell if this is drywall or plaster? I figured a trained eye may be able to see more than I can.

[ View Image ]

Thanks.

 

I'm leaning toward plaster. I've never seen drywall that tight against an electrical box.

 

I'd say yes, plaster.. It could be over 1/2" plaster over gypsum lath which is my guess given the age of the house or it could be veneer plaster over 1/2" blueboard. I think the former is more likely. The smear on the inside of the box looks like plaster, too.

Now maybe sometime someone put some texture over the plaster. If that is the case it is probably done with joint compound which should scrape off easily. If the texture is in the plaster and you really don't like it the easiest way to get rid of it is to put a coat or two or three over what's there until is is flat and smooth, then sand and prime and paint. You might not be doing the value of the house a service by covering up that good plaster.

Can you post a picture of the texture? You might need some side lighting to show the texture.

What rooms have the texture you dislike?

Are some of the rooms like the kitchen and bathroom as smooth as glass?

 

The kitchen and bath have wallpaper but the living room and hall way have the walls exposed and they have a small texture but not like this room did. However, I've already sanded the room down to make it more like the living room. I just need to spackle, wash, primer, and paint now.

Thanks for you help.