Caulk vs joint compound to fill around boxes
#1
Member
Thread Starter
Caulk vs joint compound to fill around boxes
I have a number of places where I installed recessed light fixture boxes inside my drywall in the garage. Even though I was very good at cutting the drywall and the box fit snug, there are still areas where its open. Furthermore because the lights I installed are thin but long LED wraps, these holes are visible from certain viewing angles because light fixture cannot fully cover it from one of its side.
question is, whats the best way of sealing these empty areas?
- First question is do I seal with the fixture on/mounted or with fixture removed? Advantages of doing it without removing is clear I dont make a mess and none of the cables would get dirty. Plus these LEDs are never going to get touched and have 50 year life span (or so i hope). The disadvantage is the fixture will probably get stuck there once the stuff dries and will require cutting it next time to remove.
- Do I use a silicone caulk the one you use around window frames etc or do I use joint compound/drywall patch? Which one is better around electrical connections?
I obviously habe the same problem around switches.
question is, whats the best way of sealing these empty areas?
- First question is do I seal with the fixture on/mounted or with fixture removed? Advantages of doing it without removing is clear I dont make a mess and none of the cables would get dirty. Plus these LEDs are never going to get touched and have 50 year life span (or so i hope). The disadvantage is the fixture will probably get stuck there once the stuff dries and will require cutting it next time to remove.
- Do I use a silicone caulk the one you use around window frames etc or do I use joint compound/drywall patch? Which one is better around electrical connections?
I obviously habe the same problem around switches.
#2
Forum Topic Moderator
Pics could be helpful.
Isn't there a cover to hide the edges? Hard to say without seeing but generally you'd use j/c to make any needed repairs. If it is prudent to caulk you'd use a siliconized acrylic latex caulk which is paintable, not a silicone caulk which is not.
Isn't there a cover to hide the edges? Hard to say without seeing but generally you'd use j/c to make any needed repairs. If it is prudent to caulk you'd use a siliconized acrylic latex caulk which is paintable, not a silicone caulk which is not.
#3
Member
If it is less than 1/8" regular paint caulk will work.
If it is about 1/4", you might want use more flexible caulk such as Dynaflex.
If it is even larger, then use joint compound.
Siliconized caulk will be ok, but don't use 100% silicone. Silicone is not paintable.
If it is about 1/4", you might want use more flexible caulk such as Dynaflex.
If it is even larger, then use joint compound.
Siliconized caulk will be ok, but don't use 100% silicone. Silicone is not paintable.
#4
Not sure why you can see openings around the fixtures,as mentioned some pics might be helpful.
Geo
Geo
#5
Group Moderator
Caulk and joint compound can be used as lambition mentioned. I have seen crack lines appear eventually though and I've even seen big chunks of joint compound eventually fall out. Best for the long term is a cover plate. Many stores and online sell round cover plates. You probably cannot mount the cover plate with your fixture but you can cut off the part of the plate you need to cover the hole and glue it in place with painters caulk. Then paint it to match your ceiling.
#6
Member
Thread Starter
I can see them if I stand 10-12’ far away and look at it at a tight angle. This is because the hole itself is about 4” diameter and so is the light fixture’s width on its side. And some of the fixtures are not sitting flat because my ceiling isnt flat/fixture isnt perfectly level.
#8
Member
It does if you need to block smoke or fire propogation.
But, it is rarely used at the various device outlets, at least in homes.
I will admit I have used the red stuff when sealing up a load center cutout on a garage, X rated sheetrock firewall.
But, it is rarely used at the various device outlets, at least in homes.
I will admit I have used the red stuff when sealing up a load center cutout on a garage, X rated sheetrock firewall.
#10
Member
Thread Starter
HEre is a picture. I went with joint compound in the end.
The issue is ceiling and/or light fixture arent flat. So when you stand far away (which you can in a 10-12 ft long garage), the box’s home creates a shadow/light difference and you can tell its there. The fixture is 4’ long wrap but its only 3 3/4” wide. So it covers the box barely.
The other problem is I have a very strange drywall in my house. Its always two layers and its neither 1/2” nor 5/8”. Bunch of contractors told me they dont make sheetrock that wodth anymore. As a result when I use these types of mounts, the box never sits flush with sheetrock but is recessed 1/8” maybe a tad more 3/8” recessed creating that “hole” there and when light is on the hole becomes visible.
The issue is ceiling and/or light fixture arent flat. So when you stand far away (which you can in a 10-12 ft long garage), the box’s home creates a shadow/light difference and you can tell its there. The fixture is 4’ long wrap but its only 3 3/4” wide. So it covers the box barely.
The other problem is I have a very strange drywall in my house. Its always two layers and its neither 1/2” nor 5/8”. Bunch of contractors told me they dont make sheetrock that wodth anymore. As a result when I use these types of mounts, the box never sits flush with sheetrock but is recessed 1/8” maybe a tad more 3/8” recessed creating that “hole” there and when light is on the hole becomes visible.
#12
Member
The issue is ceiling and/or light fixture arent flat. So when you stand far away (which you can in a 10-12 ft long garage), the box’s home creates a shadow/light difference and you can tell its there. The fixture is 4’ long wrap but its only 3 3/4” wide. So it covers the box barely.

The other problem is I have a very strange drywall in my house. Its always two layers and its neither 1/2” nor 5/8”.
What is your size?
All sizes, except 3/8" is readily available in hardware stores in my area. 3/8" is a bit harder to get, but not impossible.
When the surface of existing drywall is in bad condition or have wall papers, it sometimes is easier and cheaper to just install another layer of drywall. Usually done with 1/4"
Otherwise, you have to skim coat entire ceiling or wall with joint compound, which is labor intensive and very dusty when sanding.
When I find a wall or ceiling with wallpaper during remodel, I usually just remove entire drywall and put new wall on. Same with textured ceiling.
#14
Member
Thread Starter


Btw I designed everything so very large portions of the cable was concealed inside sheetrock. At one point I went from side to side of the entire 2 car length and some more, about 15’, using fish tape. But some parts of the cable still had to be stapled on the ceiling regardless, probably about 10% or less. For a DIYer, I think I did good
