Part I: How to Repair a Drywall Crack that Flexes with the Seasons

Series: Flexible Drywall RepairPermalink

Make enduring repairs to your drywall with products that stretch.

Have any cracks in your ceiling or walls? Repair them yourself with a rotary cut-out tool, a utility vacuum, a tube of elastic Big Stretch caulk, and a couple of drywall knives.

What the Crack?! Permalink

Upon the purchase of our home we inherited two ceiling-spanning cracks, the smallest of which covered the width of our hallway. This is the crack that I fixed first due to a combination of its shorter length and me not really knowing what I was doing. Both cracks seem to have been “fixed” before, so it’s unlikely that I could accidentally make the cracks any worse (aesthetically or structurally) than they already are.

Most cracks found in a home are due to seasonal expansion and contraction of the home’s wood framing. I’ll cross my fingers and hope that this is the cause of our cracks, instead of the other explanation which is structural or foundation problems. It’s also possible that these cracks appeared once the home settled, so perhaps there’s been no movement since the first cracking.

My Random Orbit Sander (and Accompanying Dust Mitigation Device) Permalink

The first thing I did was sand down the gratuitous amount of drywall patch that had been previously applied along the breadth of the crack. I used a variable speed random orbit sander to do this. Otherwise I would have needed to use a copious amount of sandpaper and elbow grease, as if I were a provincial (and not a Real Gospodar).

My orbit sander can be connected to a utility vacuum or other dust collection device. Thankfully I own Shop-Vac so this should have been easy, except that my model has a 1.5” hose, which is atypical amongst utility vacuums. I had a difficult and expensive time finding the right way to connect the two tools.

I don’t have any photos of me operating the orbit sander (I’m a one man show), so you’ll need to use your imagination. All you need to do is turn on the Shop-Vac, then the orbit sander, and get to work.

I had good luck applying pressure to the sander and rotating it myself in alternating clockwise and counter-clockwise rotations. I used two discs of the 80 grit sandpaper, although it’s possible I could have used the initial disc a little longer. I wasn’t entirely sure if I had thoroughly used the disc or not just by looking at it.

How to Connect Dewalt to Shop-Vac, an Aside Permalink

For posterity and Google here is everything one needs in order of orbit sander to utility vacuum:

  • DeWalt DWE6423K Variable Speed Random Orbit Sander, 5”
  • DeWalt DWV9000 Universal Connector
  • DeWalt DWV9190 Large Hose Adapter
  • POWERTEC 70148 Dust Control Flex Cuff with Hose Clamps, 2-1/2”
  • WORKSHOP Wet Dry Vacuum Adapter WS25055A Wet Dry Shop Vacuum Adapter Combo Kit (solely for the 2-1/2-inch to 1-7/8-inch adapter)
  • Shop-Vac 5873410 6.5-Peak Horsepower Right Stuff Wet/Dry Vacuum, 10-Gallon

Safety, First! Permalink

Anytime I do a project that involves sanding I use a respirator and safety goggles because I want to protect myself from whatever ill may come from inhaling drywall dust and getting it in my eyes. I also make sure that I have adequate lighting so I don’t accidentally hurt myself or unnecessarily damage my home. I illuminate my work area with a headlamp and LED work light (or two).

A Crack Exposed Permalink

After about fifteen minutes of arm numbing and safety google fogging work I sanded down the previous owner’s drywall patch. In doing so I discovered a length of drywall tape, which wasn’t initially visible. It seems like there were two layers of patch work on top of the crack.

Goodbye Drywall Tape Permalink

I had an even longer length of drywall tape to pull down for the second crack.

Everywhere is Dust Permalink

Unfortunately, I did not foresee the volume of dust that I would kick up into the air. The filter in my Shop-Vac was not new, so perhaps it wasn’t up to the task of sucking in all the drywall dust kicked up by the orbit sander. Regardless, I made a big mess.

Once I realized the severity of my dust situation I haphazardly taped off the pantry and covered the smoke alarm in the hallway. Don’t make the same mistake that I did and underestimate the amount of drywall dust! In hindsight I should have sealed off my working area by hanging plastic drop cloths.

Enlarge the Crack Permalink

After I sanded away the thick layer of drywall patch I enlarged the hairline crack with my cut-out rotary tool. With one hand I moved the tool along the path of the crack, while trailing with the Shop-Vac hose in my other hand. Again, my Shop-Vac was insufficient to the task of sucking the dust out from the air.

You’ll need to decide the depth of the bit you’ll be using to cut through the drywall. For the shorter hallway crack I cut out a depth of roughly half an inch. For the longer crack I made the arbitrary decision to cut out only a quarter of an inch. I have no inkling if the depth really matters, but promise to update this page if either of the two cracks ever come back (perhaps due to enlarged depth or lack thereof)!

I’ve subsequently used the rotary cut-out tool with a new Shop-Vac air filter and been pleasantly surprised with the lack of mess, so be sure to change your filter before attempting any dusty work. Learn from my mistakes!

An Enlarged Crack Permalink

Anyone have an idea about that line of small holes in the drywall?

Introducing Big Stretch Permalink

After enlarging the crack I filled it up with an elastic sealant product called Big Stretch. A tip of the hat to Lynda for her blog post, Fix Ceiling Cracks for Good, for confirming my hunch that caulk could be a pretty okay product to use when repairing a crack in a wall.

Fill up the Crack Permalink

With my caulk gun I filled up the crack with the Big Stretch caulk. I used the putty knife to push the caulk all the way into the crack. With the broad knife I scraped away any excess caulk that was left on the ceiling.

Multiple Applications Permalink

Big Stretch shrinks quite a bit as it cures so you’ll need to apply layers of it.

A Timeline of the Hallway Crack Permalink

A Timeline of the Living Room Crack Permalink

Postmortem & What’s Next Permalink

All-in-all I feel that Big Stretch is a good product for this task. I’ve noticed that one of my cracks still moves with the seasons, which causes the caulk to expand slightly out of the crack (it looks like a vein). This is what I had hoped for, although in hindsight I wonder if I applied too many layers of Big Stretch to fill the crack.

After my last pass with Big Stretch I slathered a thick layer (or two) of ElastoPatch and attempted to tool it into swirl shape with a brush (the next post in this series). I then let it cure and applied several layers of ceiling paint. Fingers crossed no one will notice my repair job, but me!

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