Drywall Patching Techniques
There are three main techniques for patching of drywall with each offering its own advantages.
The size of the patch dictates the method. But much depends on what you are comfortable with doing.
If a
ceiling repair there is a different technique.
Patch Kits - available at many of the home centers, are basically a rigid
sticky mesh. Simply apply the mesh and joint compound, let dry and sand off. These are best applied
on small holes, and indentations like from moving furniture, flying debris and stopless door knob
handles. This method offers limited success in offering an undetectable finish patch and is most
often a choice of the novice. It is intended for the horizontal wall surface.
Pre-mixed patches - many patches in small quantities bought at hardware
stores and home centers result in a gummy dried finish and are promoted as 'all purpose'. Stick
with a known brand, one that offers flow and little settle-back/slumping characteristics.
'
Easy sand' is important. But how sandable is the compound is always the question.
The more sandable products are usually found in greater quantities. Also, for patches occurring
every now-and-then, a small disposable cup will suffice as a simple mud mixing container,
and will eliminate much of cleanup.
Pull Back Technique -
to be applied on wall surfaces only, it
requires a higher level of skill. First, perform the cutout and have 4 strips of tape
at the ready; the strips should be long enough to wrap the backside of the cutout,
layered in compound, and extend at least 2" total (from by each side).
Mix the mud to right consistency, giving it a moment of pause, which will allow it
to settle, then soon re-mix soon. This will help ensure a smoother consistency.
With your compound, back-butter the replacement sheet with a taping knife.
Make note that the compound should be a consistency to fill through the tape mesh
without an excess amount of sagging.
Proceed, by putting the fiberglass strips in parallel on the backside of the cut
over the mud, each pair generally centered. The tape pairs should cross at at right angle.
Next, press the strips firmly in place to secure them.
Set the cutout in the opening - achieving a level with the wall that does not create a rise,
but rather erroring on the side of a mere countersink, if any at all - in essence, making the
planar adjustment before pressing the untouched mesh onto the outer wall. Which you can do either
by pushing in on the wallboard or by pulling out on the tape strips to come up with the desired level.
Next, gently press the tape outward in the direction of the end-cuts for all strips. This should
leave the board with the tape pairs exposed onto the wall forming a cross pattern. Now, tape the outer
exposed seams, then apply compound while firming it up to move toward a finish coat.
Standard Technique - suited for small to medium size patching, this is the
most common method in practice today. It consists of, attaching of the cutout patch to the cleared opening
either by attaching to studs or by added backers (furring strips or 1x3's) or even metal clips.
Understandably, the type of support chosen should become sturdier with an increase in patch size.
Drywall repairs gives a stepped explanation for this method.
Butterfly Technique - is only for the experienced and is not recommended
for the beginner drywaller.
Although this method is recommended for the quick fix, it does
not offer the quality of results of other techniques mentioned here.
The butterfly gets its name from the paper on the replacement cutout, left to form a lip extending by
itself from the gypsum wallboard. This lip is placed onto the existing wall, with mud already having been
applied on the perimeter of the wall - with the paper acting as a form of drywall tape. After placing
the wallboard, it is likewise knived out smooth with another layer of compound overtop.
Skimmed and then sanded as is typically done.
Patch location
If the damaged wallboard happens to be situated near or behind carpentry or casing the
carpentry may need to be pulled.
Hot mud (15 or 20 minute dry time) and drying process
Many experienced mechanics set with speed dry as normal practice for patches of all
sizes. But the beginner may wish to become more experienced and familiar with product
specifications prior to applying. Also, some drywallers seem to be in the practice
of leaving on their halogen lights directly near the patch to promote quicker drying.
Generally this is not recommended due to the fact that halogen becomes very hot and creates
a risk when unattended.
A word on taping
Become aware of knife direction and applied force as you work, since
mesh can
disentangle if pressed too repeatedly or with too much pressure.
Paper can fold up on itself. Both materials will greatly affect the end finish
and just take some practice.