In a perfect world, you could embed joint compound alone into the seam. Unfortunately, the two sheets will eventually loosen and move just enough to develop hairline cracks in the joints. Slowly the joints will start to crumble.
Drywall tape reinforces joints and lets the mud do its work.
But which one is best?
Paper Drywall Tape: Sometimes Simple and Cheap Are Best
Paper tape is exactly that: long strips of paper, usually in rolls of 75 feet or more. A slight lengthwise crease in the paper helps you fold it down the middle when using it for inside corners.
Paper tape takes some skill. You need to first prepare the wall with some drywall mud, a process known as "bedding." Then you lay down the joint tape. Then more mud.
- Cheapest type of joint tape available.
- Widely available.
- Can be used for inner corners.
- Can be ripped off by hand.
- Difficult for new drywallers to learn.
- Hard to use on corners.
- Requires initial layer of mud to get the tape to stick to the wall.
Thin Fiberglass Tape: Paper + Fiberglass
FibaTape Perfect Finish is a mesh tape that does not have the "thready" qualities of classic mesh tape. Plus, it is thinner than paper joint tape.
Yes, manufacturer Saint Gobain claims that FibaTape is 30% thinner than paper tape.
Given the thinness of the two products, this may be a moot point. But it certainly is thinner than ordinary mesh joint tape, so no more bulges.
- Thin joint tape - great for butt joints.
- Stronger than paper tape.
- No loose threads.
- Self adhering to wall.
- Must be cut with scissors or knife.
Fiberglass Mesh Tape: Not All It's "Cracked Up" To Be
When fiberglass mesh drywall tape came on the market, everybody cheered with joy. Finally, a strong drywall tape! In fact, mesh drywall tape is downright impossible to tear. It's basically fiberglass threads woven together into a tape-like form. You could hang from the stuff, it's that strong. But it does have its downsides: it is gummy and hard to handle, and it's thicker than paper joint tape.
- Extremely strong.
- Self-adhering to the wall.
- Must be cut with scissors.
- Tends to start shredding into threads.
- Gummy adhesive can be annoying - and doesn't always stick when you want it to.
- Thick tape leaves a bump in your finishing.
It is tempting to use fiberglass tape for everything. But according to Mark McVeigh, a drywall contractor for over 25 years in Pompton Lakes NJ, fiberglass mesh tape has its limitations, especially with small repairs. It seems counter-intuitive, but paper tape can work better, and Mark explains why:
I have done every small repair that you can imagine, as well as my share of new construction. I Googled the topic of your article just to see what I might find. A great deal of the work that I do now, is smaller jobs. What I am finding confirms my experience with the mesh products. I repair more joints that have cracked, both factory and butts, than almost anything else. Very often, I will be called to repair other problems and I find cracked mesh joints like crazy. I never use the product. Every time I have experimented with it, it cracks. First, it is not designed to be used with regular joint compound. It is supposed to be used with "setting compound" like EZ-Sand or Duro-Bond. These dry harder and are more resistant to cracks. That having been said, the paper-taped joint is a much longer lasting joint, and one that more resembles the actual drywall product itself.
Take your average paper tape, lay down two strips of very thin metal running the length of the tape, and leaving a small gap between the metal. That's your average metal-backed paper drywall tape.
This kind of joint tape might actually be categorized in the "corner bead" section because it cannot be used on flat surfaces. It is meant to be creased lengthwise, and then applied to either inner or outer corners. Because it's already got the crease, you don't have the creasing problems of ordinary paper drywall tape.
- Easy to crease.
- Stronger than plain paper drywall tape.
- Perfect for inner corners.
- Must be cut off with scissors.
- More expensive than plain paper drywall tape.
Paper Tape vs. Mesh: A Tale Of Two Tapes
When combined with drywall compound, paper tape provides a perfectly adequate joint.
Choose this in most cases.
- Consider whether you are working on a tapered seam or a flat seam. Tapered seams are where the two tapered edges of drywall meet, forming a shallow "valley." The thicker mesh tape will fall below the level of this valley and can be covered with drywall compound.
- However, if you are working on a flat seam (also known as butted seams), you absolutely need to use paper mesh tape. Otherwise, the thicker mesh joint tape will stick out too far and look lumpy.
- If you have joints that will be subjected to some stress (such as near to doors), use the fiberglass mesh tape.
- Inside corners need paper tape or better, metal-reinforced paper tape. It is virtually impossible to apply mesh tape to inside corners.