1. BEFORE, DURING, AND AFTER: The rules of the game are simple. If they are followed we will all win.
Some advice from USG (USG Handbook): “Gypsum board should be ordered for delivery several days in advance of installation”
Condition the drywall just as a carpenter would hardwood flooring before installing.
“In cold weather (outdoor temperature of less than 55 degrees F), controlled heat in the range of 55 to 70 degrees F must be provided. This heat must be maintained both day and night Before, During, and After entire gypsum board finishing and until permanent heating system is in operation or the building is occupied” USG Handbook
In a post on Walls & Ceilings Magazine website in March 2001: A United States lead study group was quoted as saying that “pre-conditioning interiors for just 24 hours prior to installing board can minimize cracking by some 20 percent. If board is installed without being pre-conditioned to the indoor environment, problems can appear within 24 hours after turning on the heat or A.C.” The study also cautions that propane heaters should NOT be used for conditioning as their exhaust dumps excessive amount of moisture into the interior environment. Too high or too low humidity levels before, during, and after will affect the job as well.
2. PLAN AHEAD – IT’S JUST DRYWALL- WHAT’S TO PLAN FOR?
As a drywall contractor I often get a call about starting a drywall job that is ready now and the customer is hoping I can start work next week. Well, even if I had time to do the job there is a lot of planning ahead needed before I can start. First I measure each ceiling and wall to tally up the lengths needed. Drywall is available in panels up to 16-ft long. For an 8-ft 6-inch ceiling to a 9-ft ceiling I may want to order 54-inch high drywall to span the height with only one horizontal seam. Before I start figuring lengths and widths of panels needed I should check for access. Can I get a large truck close enough to the structure? Because larger deliveries are usually boomed in you need to check for power lines, tree limbs, as well as freshly dug ditches. Hopefully the contractor has thought about booming in upper story deliveries. If an installed window opening is too small then maybe the rough opening will work so leaving the window out will be a big help. I have been on a job where the plywood sheathing has been left off a wall so drywall can be brought in. If leaving windows or sheathing out is not an option then scheduling an early delivery may be necessary.
3. VERTICAL VS. HORIZONTAL – WHICH IS PREFERRED?
In residential construction where the walls are 9-ft high or less attaching the drywall horizontally can reduce the lineal footage of seams by as much as 25% over vertical attachment. On higher walls like in a stairwell or on the end wall in a cathedral room, horizontal is still the way to go. Transitions areas such as the floor joist beams or top plates of walls where studs continue on to the rafters can be spanned so that seams are located off these areas. Horizontal attachment also increases shear strength of the structure and seams are usually at a more convenient height for finishing.
4. PARALLEL VS. PERPENDICULAR; WHAT’S THE DIFFERENCE AND WHY NOT JUST HANG THE DRYWALL IN THE DIRECTION THAT RESULTS IN LESS BUTTED SEAMS?
The accuracy of on center spacing of the framing is very important if attaching drywall parallel in joists on ceiling. Cutting the beveled edge off so the seam lands on a joist is really not an option as far as the finisher is concerned. Drywall is approximately 3 times stronger in the long direction. Accordingly, drywall hung perpendicular to the framing is stronger than drywall hung parallel, so it is less likely to sag. If attached, perpendicular lengths can be cut so that the butt seams fall where desired. Yes we are always trying to avoid butted seams, but an occasional butt seam is better than a ridged seams running the length of the ceiling or sagged drywall between joists. Perpendicular gives the structure greater strength. Drywall floats over slightly uneven joists, making them less conspicuous.
5. ATTACHMENT-MOST PEOPLE KNOW THAT SCREWS ARE PREFERRED BUT WHY AND WHY DO PROBLEMS STILL OCCUR WITH SCREWS?
Screws are faster to install than nails, they do less damage to the drywall panel when set, and they hold the drywall tighter against the framing. If a screw is set too deep it has torn the face paper and is weaker. If the framing the drywall is being attached to is bowed in the screw may not be able to pull the panel tight so if the walls moves or is hit the screw will pop loose. If there was poor heat or humidity when the drywall work was being done and then the heat is turned on and the humidity lowered then lumber shrinks more than the drywall and screws pop loose. Screws only need to penetrate the framing 5/8 of an inch, longer screws are more likely to pop if lumber shrinks. Drywall is affected by settling and structural movement which can cause screws to show.
6. DRYWALL ADHESIVE: IS THE EXPENSE JUSTIFIED?
Screws hold the drywall in tight in just a small percentage of the area in contact with the framing compared to the entire length where adhesive is used. Screws hold just fine as long as everything stays stable. When lumber shrinks the drywall is no longer tight so when something bumps the surface, the screw can pop loose. Also drywall attached with screws only doesn’t add much shear strength to the structure. Adhesive adds shear strength and eliminates fastener pops by adhering the drywall to the framing. It also reduces the potential for bowing or sagging. You can use fewer screws up to 75% less. Adhesive creates a stronger bond than just screws. Adhesive is not affected by moisture or changes in tempt. The adhesive also bridges minor irregularities in the framing.
7. BUTTED SEAMS – WHAT ARE SOME TIPS THAT WILL HELP TO REDUCE SEEING THESE SEAMS?
The first step toward reducing problems with butted seams is to reduce the number of butted seams. Using longer sheets (drywall is usually available up to 16-ft long) is the best way. Also on longer walls which are often broke up with a doorway or a window, place the butt seam above a doorway or above and below a window. This will make for shorter seams that are often partially hidden by trim work and curtains. (Note: keep the seam off the edge at least 7 inches to keep it more stable and away from mitered trim areas).Make sure you use screws and adhesive to attach the drywall to the framing at butted seams. Paper tape embedded in a setting compound will give you an even stronger seam. Try to keep the butted seam toward the corners of walls and ceilings so they are in less conspicuous areas. The problem with butted seams is that because the ends of drywall are not beveled the taped seam is a bump. Filling a recess is much easier than trying to blend in a bumped up area. Also the joint is a weak joint because fasteners are usually placed to close to the edge and it is attached to a single framing member so if something moves (expands or twists) the seam will ridge or crack.Something I have been doing for years is called back blocking. The seam is purposely placed between the framing members and attached to a specially designed piece of framing that attaches to the back of the drywall only. The seam is pulled in slightly. It is easy to hide and it is very stable because it is floating.
8. MISALIGNED FRAMING AROUND DOORS AND WINDOWS; WHY DO I SOMETIMES HAVE TROUBLE FASTENING THE DRYWALL TIGHT AROUND OPENINGS?
Doors and windows are usually framed with two studs on each side and a header on the top with a 2x4 or 2x6 on the top and bottom of the header. There really is a lot of framing material that quite often isn’t nailed together with the greatest of care. When I attach the drywall to these areas I try to keep the screws out of the wide surface of the header to avoid pops and I also keep the screws close to the edges so they will be covered by the casing. If the framing is misaligned even as little as 1/8 of an inch the fasteners break through the drywall because it will not bend in enough. At the corners I have even had the drywall crack when trying to screw the edges in tight because the header is not flush with the studs.
9. POOR NAILERS AT INSIDE CORNERS; WHY DO FRAMERS GIVE US SUCH POOR NAILING AT INSIDE CORNERS?
I usually have pretty good framing along edges of ceilings. If there is a ceiling joist within 6 inches of the edge that is all I need. Sometimes the poorly attached scrap lumber attached to the top of the walls is difficult to attach to. It’s the nailers at the wall inside corner that really drive me crazy. I prefer to attach my drywall with screws. I would love to have studs 2-inches from each corner, that way I could easily use my screwgun and get the screws in straight and properly set. Sometimes when the corner is framed, one stud is nailed a little behind the other stud. When this is done I have to make certain that the wall with the narrow edge is hung first and even then it is difficult to fasten to with a screwgun. The abutting wall then also ends up having a narrow edge to attach to. I really would like to see the studs back a couple of inches and I would bet the insulator would also.
10. WHY IS HAVING A CLEAN JOBSITE IMPORTANT BEFORE, DURING, AND AFTER THE DRYWALL WORK IS DONE?
In most homes drywall is everywhere so the drywall contractor has to get into every room and in every corner of every room, even the closets. The panels are long, heavy, and cumbersome. After the drywall is attached the tapers have to apply three or four coats of compound, followed by sanding. The tapers have to have a steady hand as they stay focused on their work. If there are tools and materials and debris scattered all over the place the quality and quantity of the work will suffer. Likewise when the drywall work is complete the next group of contractors is ready to come in and get started. They shouldn’t have to deal with drywall scrap, dropped joint compound, filled electrical boxes, and thick dust. The customer should notice the quality of the work done rather than the mess left behind.
11. JOIST HANGERS: I KNOW THEY ARE IMPORTANT BUT HOW IS THE DRYWALL CONTRACTOR SUPPOSED TO HIDE THE BUMPS IN THE DRYWALL THEY OFTEN CREATE?
When I first went into the drywall business joist hangers were rarely used. Now I see more and more of them and they can create some real problems. I know what they are there for and that they are important, but unless it is a deck they should be flushed with the ceiling framing or maybe even left up a little .I usually span areas with beams and joist hangers because a seam in this area is difficult to hide and is more likely to crack if settling occurs. If the hangers are low a seam in that area would definitely be ridged out. Let’s say the low hangers are carefully located at the center of the sheet. This still does crown the drywall down some and under certain lighting conditions may be visible. It is also difficult to attach the center of the sheet; fasteners often pop through when installed and are more likely to pop when structural movement occurs.
12. WHAT ARE SOME REASONS TO FUR A CEILING?
Sagging insulation can create some real fastening nightmares. It is very difficult to hold the drywall up tight with screws when it is being held down by the pressure of sagging insulation. Extra help is necessary to push up on the drywall as it is screwed tight and extra screws are necessary. You are more likely to have problems with popped screws and sagging drywall later. If you have a low beam or low joist hangers the few extra dollars it will cost to fur the ceiling is money well spent. You won’t have to explain to the customers later why there is a bump or a low area on the ceiling.I see it quite often; ceiling joists start out going in this direction and then change 90 degrees and sometimes back again. How am I supposed to properly hang drywall to this mixed up framing? Fur the ceiling please. I like to use a metal acoustical furring when I have to fur a ceiling (RC1). It does everything wood furring does plus it offers excellent sound control and reduces fastener pops and joint cracking.
13. HIGH WALLS AND TRANSITION AREAS FROM ONE STORY TO THE NEXT: IS THERE ANYTHING TO HELP MAKE THESE AREAS EASIER TO HANG AND TAPE?
Walls in stairways have the lower wall with the floor joist beam setting on top of it and then the upper story wall on top of that. Gable end walls usually have walls framed the height of the lower ceilings and their framing sets on top of this wall going up to the ceiling rafter.
These transition areas are very poor places for a seam. If the framing is in or out of plumb, then a seam in this area will be difficult to hide. Also this area is where settling or movement is likely to occur so the seam may crack or ridge. Start at the top or the bottom with a panel ripped down less than 48-inches.(Keep ½” off the floor to allow for settling) Whatever measurement allows you to span the entire area with the drywall. Fasteners in this area may also be difficult to install and are more likely to pop later. I suggest using more drywall adhesive and fewer fasteners. I have had excellent results using screws and adhesive above and below the transition area and only adhesive at the transition area.
14. CAN POORLY CROWNED LUMBER MESS UP A DRYWALL JOB?
Poorly crowned lumber can mess up a lot more than the drywall job. As long as I hang the drywall perpendicular to the framing I will have less problems with any seams showing than if I went parallel to wavy framing. Even a beveled edge seam attached to a crowned stud or joist will be crowned out and difficult to hide. If the drywall is hung perpendicular it just flows over the framing and the seams are easy to finish. If the framing is in and out too much fastening may be a problem. Screws may pop loose later. The real problem will show up when lights are turned on or a chair rail or countertop is installed.
15. WHOSE JOB IS IT TO SHIM OUT THOSE FIBERGLASS SHOWER UNITS?
I don’t think it is the drywall contractor, but I don’t think the drywall contractor should just cover these areas without mentioning it to the GC first. If these areas are left un-shimmed I have to fasten the drywall through the flange and into the framing close to the shiny fiberglass, risking scratching with the screwgun, and then attach along the top plate of the wall. When the top side pieces are butted to the back wall piece there is a nice gap in the top corner. The vertical edges are just as bad especially when an outside corner is only inches away. We all know that most plumbers aren’t going to shim out a tub and most drywall contractors are being paid by the foot so they just keep on going. I would have to say it is the GC’s job.
16. FIRE STOPS AT SEAM HEIGHT: SEEMS LIKE A LOGICAL LOCATION BUT DOES IT CAUSE ANY PROBLEMS WITH THE DRYWALL FINISHING?
Fire stops located at the center of a wall can create a nightmare for a drywall contractor. At first it seams like the ideal location, a nice convenient height for nailing a piece on and also it is great backing for an extra strong horizontal seam. If the blocking or nails used to attach the blocking stick out past the plain of the framing then it will ridge out the seam. Maybe just here and there along the wall, but that is still enough to cause problems that are very difficult to fix and which may not be noticeable until after the people have moved in and turned on their reading light.Take your time when installing the fire-blocking, keeping nails and framing flush and keep it off the seam location, maybe up 7 or 8 feet.
17. RECESSED LIGHTS: HOW DO YOU KEEP TRACK OF WHERE THEY ARE OR FIND ONE AFTER THE DRYWALL IS ATTACHED?
Recessed lights have become more and more common. Sometimes there are 3 or 4 to cut out of a single sheet of drywall. When drywall is hung the openings are cut after the panel is tacked in place. It is really easy to forget to cut one out occasionally. The electrician knows there is one someplace in the area and that there should be 50 total he thinks, but we only count 48. A few years ago an electrician showed me that under each light he put an x on the floor with a marker. If you see an X on the floor, but no cutout above it then you missed one. I like to take this one step further and use a self leveling laser level to mark the location on the floor. This way any missed lights can be accurately located.
18. DOES A POOR INSULATION JOB AFFECT THE DRYWALLING JOB?
There are three things that can mess up a drywalling job as far as insulation goes. Sagging insulation in ceilings can make properly attaching the drywall impossible. Either staple the insulation up higher along the inside edge of the framing or fur the ceiling. Overstuffing a narrow bay may make attachment in that area difficult. Sometimes an entire ceiling is overstuffed because the framing is not deep enough to accommodate the high R value. The framing should have been built out to create more room. I know this will get a response form some readers, but I don’t like to see the paper flange of Kraft insulation stapled over the face of the framing. This method contributes to the sagging or bowing out of the insulation which causes fastening problems. The thickness of the paper edge along with the protruding staples creates a problem for fastening. Poorly attached drywall and a real increase in fastener pops are a direct result. Maybe use furring over the kraft-faced insulation on the ceilings and un-faced with poly on the walls.