I had a 30" x 72" window removed and will be covering the void with 1/2" sheetrock. As such, there will be butt joints around the entire perimeter of the patch (if you can call it that). Since butt joints need to be feathered out farther, does it make sense to just skim coat down the middle of the patch as well, as opposed to doing only the perimeter? For instance, if I feather out 12" on the butt joints, there will be about a 6" strip of exposed paper down the middle. Does it make sense to go ahead and skim coat this narrow strip as well? Is there a rule of thumb for determining when to skim coat an entire area as opposed to just the perimeter? BTW, I will be using setting type compound for the greatest strength.

 

Setting compound tends not to be the best choice for a skim coat. I would stick to drywall compound and do the whole thing based on your description.

 

Sorry, I should have been more clear--I meant I'll be using setting type for the taping coat, then lightweight drying type for the top coats. Whole thing it is. Thanks.

 

I'm not crazy about using a setting compound for skim coating either. I almost always use regular j/c for the final coat. I probably would skim the final coat.

 

If you do not fill the centre area, you may be able to see the two butt joints independently after the wall is painted. If you fill the centre, the finished butt joints may not be quite as easy to see.

 

Hold a flashlight or utility light tight to the wall such that the beam of light shines across your patch. Any major irregularities will show up as shadows and will tell you what you need to do as far as skimming. If using paper tape with setting compound, wet the tape first and mix the compound a little loose. The fast setting of the compound sometimes has adhesion issues if the tape is dry. The only time I use regular joint compound is for skim coating- for everything else, I use setting type compound. I also like the brand that big orange carries vs big blue's preferred offering.