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How to Cut Drywall

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how-to-cut-drywall-pic1Why do you need to learn how to cut drywall? Drywall is a common product in most homes. From time to time repairs need to be made or drywall needs to be removed to repair other things. Another scenario might be making a home improvement. Finishing a basement or adding a closet will involve cutting drywall.

Depending on the situation and the type of drywall the way you cut it can vary. This article discusses the ways you can cut drywall with the tools you have at your disposal.

For related drywall repair topics see the articles 'How To Fix Drywall', 'Patching Drywall', 'Repairing Large Holes in Drywall' and 'Taping and Mudding Drywall'.

I do mention some special tools for completeness, but most homeowners will not possess them or have access to them. You do not need special tooling to cut drywall. They just make it faster when you do it all the time. The right tool for the cut you are making is also discussed.

How to Cut Drywall - Information

This article on how to cut drywall is informational. It is intended to provide basic how to skills to get a job done. We do not classify this information as a repair. We provide you with information about materials and techniques. The information below gives you a summary of the various things involved.

Types of Drywall

Learning how to cut drywall depends a little on the type being cut. It is possible for you to have four or more different kinds of drywall in your home. Most of these types cut in a similar way. This is with the exception of cement board which is not really drywall at all. This material is used in bathrooms because it does not rot. Knowing the types will help you when you learn how to cut drywall.

The following is a list of common types of drywall found in residential construction:

  • 1/2" Regular Drywall - This is probably the most common type you will find. It is used on most of the walls and ceilings. It is made of a gypsum core sandwiched between two layers of heavy papers. This type is the easiest of all to cut.

  • Tools Needed: Utility Knife; Keyhole Saw; Tape Measure;
    Optional Tools:Tee Square; Router
  • 5/8" Firecode Drywall - This drywall is thicker than the half inch material. It also has a special gypsum core that resists heat and provides fire protection. The heavier fibrous core is harder to cut but still possible.

  • Tools Needed: Utility Knife; Keyhole Saw; Tape Measure
    Optional Tools:Tee Square; Router
  • Moisture Resistant Drywall - As the name implies this drywall is used for areas like bathrooms that have higher humidity. Sometimes called green board (it comes in different colors now depending on the manufacturer), it is in between regular and firecode for difficulty.

  • Tools Needed: Utility Knife; Keyhole Saw; Tape Measure
    Optional Tools: Tee Square; Router; Circle Scribe
  • Glass Mat Drywall - This drywall is a variation of moisture resistant drywall. With the prevalence of mold issues, glass mat drywall was developed to eliminate mold growth on the drywall. The facing is made of fiberglass instead of paper. Mold will not grow without organic material present. You may find some of this drywall in a newer home.

  • Tools Needed: Utility Knife; Keyhole Saw; Tape Measure
    Optionals Tools: Tee Square; Router; Circle Scribe
  • Cement Board - A further step in moisture resistance. This is not drywall at all (drywall is made of gypsum, cement board has no gypsum in it).It is made by sandwiching a special cement core between two layers of fiberglass mat. This material is used behind ceramic tile and marble for high moisture areas. This material is the hardest of all to cut.

  • Tools Needed: Tape Measure; Diamond Circular Saw Blade; Circular Saw
    Optional Tools: Tee Square; Router; Carbide Router Bits

The types of drywall listed above may be found in your home. Many homes only have one or two kinds. Don't be shocked if you find something you are not familiar with. The cutting methods below will tell you which methods are appropriate. In addition we will discuss which tools to use for each cut. Learning how to cut drywall is not that difficult when you know a few tricks.

Using a Utility Knife to Cut Sheetrock

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Using a utility knife to cut drywall is the your first choice. The drywall has a paper facing on it, that the utility knife is well suited to cut.

The first thing you will need to do when you cut drywall is to size the piece. A tape measure and utility knife are the tools for this. For a patch where you are fitting into a cut out you want to size the piece 1/8" to 1/4" smaller than the hole you are filling. Get your measurements for the piece first. If you want use that old carpenter rule, measure twice, cut once.

To begin your cut you score the paper on the face side of the drywall. For a piece that is close to four feet wide you want to cut clear across the four foot dimension of the drywall. After you have done that you break the piece back and cut the paper on the back side. Repeat this step to size the piece the other way.

Keeping cuts straight when using a utility knife to cut drywall can be challenging. How do you do it? Great question. There are a couple of ways to do that. You can draw a line on the face layer with a straight edge and a pencil. Then you carefully follow the line with the utility knife. The next option would be to mark the sheet and then use a metal straight edge or a tee square to guide the blade. See the article 'Using a Drywall Tee Square'.

Another very effective method is the one used by professional drywall hangers. You hold the end of the utility knife against the end of the tape measure and hold it in place with your thumb and forefinger. Then you pinch the tape measure at the correct dimension with your other thumb and forefinger. You run you finger along the edge of the drywall and score the board at the same time. You need to keep the tape more or less perpendicular to the side you are measuring from.

This method requires some practice and may not be practical to learn if you only have one or two pieces to cut. Want to try it? Use some scrap pieces to develop your skills.

When you are cutting a small piece out of a larger sheet you will need to use the keyhole saw (discussed below). Cut the drywall with the keyhole saw in one direction and score it and break it in the other one.

Cutting Holes With a Keyhole Saw

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Using a drywall keyhole saw for cutting out boxes and openings is common. A keyhole saw as the name implies cuts drywall by sawing it. It has a sharp point that can be bored through the drywall to start a hole. Once the saw is through the drywall you saw along the line. At times you can use a keyhole saw to cut in from the edge of a sheet.

Another thing a keyhole saw is good for is cutting out an opening. Electrical boxes or light fixtures are a good example. You need to measure from the edges that the drywall piece will abut to.

Lay out the opening on the new piece of drywall. With the lines in place you can cut out the opening using a drywall keyhole saw. Use the point to bore into the drywall. Saw the opening out from there.

Some pieces of drywall may need several things cut out of them. Bathrooms and kitchens are examples of this. Using a drywall keyhole saw is a must at these locations.

Using a Drywall Tee Square

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When available, using a drywall tee square to cut drywall is a time saver. A tee square as the name implies looks like a tee. It is designed to provide a guide for cutting long sheets of drywall to the desired lengths.

The long leg on the tee square is four feet long. The tee at the top aligns with the long edge of the drywall. The self squaring feature gives you a good edge to cut the drywall along.

Use your knife or a pencil to mark the desired length of the piece you need. Position the tee square at the mark. Use hands, knees and feet to hold the tee square in place while you run the utility knife along it. Snap the drywall and score the back to complete the cut.

Using a drywall tee square as a straight edge to make smaller cuts also makes sense. A tee square is not a big investment, around $20. Weigh the cost against how often you will likely use it. Are you in this home repair thing for the long haul? It might be worth the investment.

Cutting Electrical Outlets With a Router

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Cutting drywall with a router can save time and improve the quality of the installation. One note of caution, they generate a lot of dust and can require a lot of clean up.

Drywall routers are not quite the same as a router you may have in your wood shop. They are similar to a laminate router that is a specialized tool. Standard drywall router bits require an eighth inch shank. Heavy duty bits may be a quarter inch shank. The point is that a standard router is not set up to act as a drywall router.

When you get down to the nitty gritty, a standard router might be converted to a drywall configuration. That is beyond the scope of this article. It is possible but not practical. Instead of cutting drywall with a router, I recommend using more conventional cutting techniques for simple repairs.

Drywall routers will cut around an opening when the drywall is in place. When you use a router to cut an opening you first mark and approximate center of the opening on the drywall. Then you tack the sheet in place. Push the router through the drywall at the mark. Move laterally to the edge of the opening. For an electrical box or light fixture, you jump to the outside of the rim and follow the edge counterclockwise. For a plain cut out you follow the inside of the opening with the router. Make sure you push the wires back into the box before routing the drywall.

You can also use the router to cut out opening on a sheet before you put it in place. This takes some practice as the router cuts the board easily and does better when it has something to follow. Some drywall hangers score the drywall and the router will track in the groove.

Most homeowners do not have a drywall router and it is probably not worth purchasing one for a small project. Got a tool fetish, you can own one of these high powered babies for around $75. With a little creativity you can even manage to justify it to your spouse.

How To Cut Cement Board

Learning how to cut cement board is important if you have a bathroom remodeling project. Can you cut cement board with a utility knife? That is a $64,000 question. The answer is yes, but it is not fun. As mentioned above cement board is two fiberglass mats with a cement core.

You and use a utility knife to score the fiberglass. You have to score it several times and the blade will have a tendency to jump out of the groove.

With the fiberglass mat scored the cement board will break similar to drywall. The problem is that it does not break cleanly or pretty for that matter. Sometimes hunks will break free that are not anywhere near the line that you scored.

A much better choice is a diamond circular saw blade. Cut the cement board the same way you would cut plywood. Do it outside or in the garage. Cutting it dry with a diamond blade will generate a lot of dust. Wear a mask.

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Summary

For related drywall repair topics see the articles 'How To Fix Drywall', 'Patching Drywall', 'Repairing Large Holes in Drywall' and 'Taping and Mudding Drywall'.

Cutting drywall for you home repair projects should not be a big problem. A few tools and a couple of tricks and you are in business. Not really rocket science and since you are taping over it, it is forgiving. Are you glad that you learned how to cut drywall?

Maybe 'glad' isn't the right word. How about satisfied? Is that a better word? All right let's concede that it would not be your first choice for a fulfilling experience. You do have to admit, however, that it did save you a few bucks.

Using a Dustless Drywall Sander

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You will appreciate dustless drywall sanding a lot more after your spouse is done yelling at you for making such a mess. Drywall dust is, without a doubt, one of the messiest substances known to man. The dust is so fine and it travels fast. It is amazing where it can get and how much of it can get there.

Tracking it through the house is another popular mistake. All of the praise you can get from a good drywall job will be negated by the scorn you will receive from making a mess.

For related information, see the articles 'How To Patch Drywall' and 'Taping and Mudding Drywall'.

Drywall dust does not have to win. It does not have to ruin your drywall repair project. Find out the options you have for dealing with drywall dust. It could be as simple as the kind of drywall mud you use.

You have two options when it comes to dustless drywall sanding. One would be to deal with the dust before it gets everywhere. The other would be to not create any dust in the first place. The method you choose will depend on several factors. Doing a better job of finishing the drywall can also help.

Containing Drywall Dust

Do not underestimate how pervasive drywall dust can be. It has the ability to get everywhere. It will put a layer of fine white powder on everything. When you are planning on dry sanding, you need to protect the area.

Containing the mess is a good idea with any repair project. Cover the floors before you start. Drape plastic over the doorways and seal them with blue masking tape. Put walk off mats down wherever you will be going in and out of the area.

Another silent enemy is your heating and cooling system. Cover up the registers and cold air returns. Dust that gets sucked into you heating system can wind up spreading through the whole house. Even when you use dustless drywall sanding techniques it is a good idea to isolate the area.

Drywall projects are among the messiest you will get involved with on your home. The other problem is that it normally takes place inside of your home.

Vacuum Sanding Drywall

Vacuum sanding drywall is another option. You do this by attaching a sanding head to a shop vac. This method has the advantage of achieving the same quality as conventional sanding. The vacuum cleaner captures the dust as it is generated. Sanding heads that can attach to a shop vac can be purchased for around $20. Not a big investment for saving yourself some cleaning.

Unfortunately, there are a few issues to contend with. Vacuum sanding drywall with a shop vac is not totally dust free. Some dust escapes the suction and can still get in the air. Drywall dust is very fine and can clog a filter on a shop vac very quickly, even if the filter is new. When this happens the shop vac will start to blow out as much dust as it picks up. Not a pleasant thought. Purchasing the sanding head is not a major investment. However, it is still an expense.

You need to use sanding screen with this type of sanding head. The holes in the screen allow the air to pass through. You need to purchase the screen and a sanding head before you can start. Make sure you have a clean filter for the shop vac. Sand the drywall the same way you would with a regular sanding head. Sand lightly, in long even strokes until the surface is smooth. Use your hand to make sure the area is smooth.

Check the filter often, cleaning as needed. The mess will be massive if the filter clogs. After you are done you want to clean the filter thoroughly.

Dustless Drywall Compound

A few years ago a new product was introduced to be used in the war on drywall dust. Dustless drywall compound made its debut and dustless drywall sanding took a giant leap forward. The United States Gypsum company started producing a light weight dustless drywall compound.

Light weight drywall compounds have always been a friend to do it yourself homeowners. They are easier to work with and require less sanding than the older standard compounds. Adding dust free technology to an already popular compound was a great innovation.

Dust free does not mean mess free. The way the compound works is that the dust particles stick to each other forming larger particles that fall harmlessly to the ground. This residue is easily swept up and disposed of. The fine white dust that becomes airborne is not a factor.

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With this product, dustless drywall sanding has never been easier. Most home supply stores carry this compound. The USG brand is called "Sheetrock Joint Compound - with Dust Control". It is sold in one gallon and three and a half gallon pails.

Summary

Patching and repairing drywall is one of the messier home repair projects you can tackle. The white powder, the gypsum, can get everywhere. When sanded the white powder is very fine and gets in the air. Once it is in the air, it travels through the house, putting a layer of fine white powder on every surface.

The smart thing to do is employ some form of dustless drywall sanding in your project. You can eliminate most or all of the fine white dust. This will make everyone in the house happier. It will also save a lot of cleaning time. You are already tired from the repair project. No need to get exhausted cleaning up afterward.

Wet Sanding Drywall

Details

Wet sanding drywall is a common method that is used to smooth the surface of the drywall compound. It really isn't sanding at all. Instead a sponge or rag is used to dissolve the drywall compound.

For related drywall taping and finishing information see the articles 'Taping and Mudding Drywall', 'How To Patch Drywall' and 'Fixing Holes in Walls and Ceilings'.

Advantages of Wet Sanding

This method has some advantages. The first would be that it does not require any special tools. A sanding block and a rag or a sponge along with a pail of water are all the tools that are needed. Done carefully, this method can yield a smooth surface that is ready for paint. The biggest advantage to wet sanding drywall is that there is no dust at all. All the excess drywall compound is dissolved by the water and winds up in the pail of water. Great!

Drawbacks to Wet Sanding Sheetrock

Wet sanding drywall does have some drawbacks. First the feathering of the edges is not quite as smooth as regular sanding. This may or may not be noticeable after the patch is painted. Second, it is very easy to remove too much compound. When this happens you are forced into coating the area again. Lastly, you can groove the surface without realizing it. Again, when this happens you will have to coat the area again.

How To Wet Sand Drywall

Always use something that is flat and fairly stiff for this method. Never use just a rag and your fingers to finish the drywall. You will groove it almost immediately. They do sell sponges at drywall and home supply stores for this purpose. They are not expensive and work pretty well. Use a damp sponge, not soaking wet. Wring it out often while you are smoothing the surface. Make several light passes and do not put too much pressure on the sponge.

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Another option for this type of dustless drywall sanding would be a sanding block and a rag. The same principles apply, not too much water and light pressure. Don't try to do too much with each pass. Don't remove too much compound.

How To Clean Up Drywall Dust

Details

Do not underestimate how pervasive drywall dust can be. It has the ability to get everywhere. It will put a layer of fine white powder on everything. When you are planning on dry sanding, you need to protect the area.

Containing the mess is a good idea with any repair project. Cover the floors before you start. Drape plastic over the doorways and seal them with blue masking tape. Put walk off mats down wherever you will be going in and out of the area.

Another silent enemy is your heating and cooling system. Cover up the registers and cold air returns. Dust that gets sucked into you heating system can wind up spreading through the whole house. Even when you use dustless drywall sanding techniques it is a good idea to isolate the area.

Drywall projects are among the messiest you will get involved with on your home. The other problem is that it normally takes place inside of your home.

Dustless Drywall Compound

A few years ago a new product was introduced to be used in the war on drywall dust. Dustless drywall compound made its debut and dustless drywall sanding took a giant leap forward. The United States Gypsum company started producing a light weight dustless drywall compound.

Light weight drywall compounds have always been a friend to do it yourself homeowners. They are easier to work with and require less sanding than the older standard compounds. Adding dust free technology to an already popular compound was a great innovation.

Dust free does not mean mess free. The way the compound works is that the dust particles stick to each other forming larger particles that fall harmlessly to the ground. This residue is easily swept up and disposed of. The fine white dust that becomes airborne is not a factor.

With this product, dustless drywall sanding has never been easier. Most home supply stores carry this compound. The USG brand is called "Sheetrock Joint Compound - with Dust Control". It is sold in one gallon and three and a half gallon pails.

Drywall Hand Tools

Details

drywall-cutting-tools-pic1You need drywall cutting tools when you have a drywall repair project. Using the same tools that you use to cut wood on drywall is not a good idea. Drywall is a much different product and therefore, cuts differently. Worse yet, using a power saw on drywall can ruin the saw and make a mess that you would not think possible.

Drywall is made of a core of gypsum that is sandwiched between two layers of heavy paper. Without the paper, the gypsum will crack and break apart easily. Gypsum is a soft white or gray rock that generates dust when it is cut. Tools that do not generate dust and that are designed for cutting the paper are best.

Most small drywall projects can be handled with just a few tools. A large investment of money is not needed. Are you remodeling? Do you have a lot of drywall to install? There are other tools you can consider.

For instructions on 'How To Cut Drywall', follow this link. It takes some practice and a few tips to learn how to cut drywall like a pro.

Below you will find descriptions of common drywall cutting tools. An approximate price is included, although prices will vary from store to store. Generally, the costs will be low, for the tools you need. The tools are fairly durable and will last a long time, once purchased.

Drywall Utility Knife

drywall-cutting-tools-pic2Of all the drywall cutting tools, the drywall utility knife is the one that is used the most. Cutting the paper is the key to cutting drywall. You need to 'score' the paper on one side of the drywall first. Then you 'break' the core by folding the drywall back. Next you use the utility knife to cut the second layer of paper.

A drywall utility knife is a popular tool and most homes have them. They use replacement blades that are available at hardware and home supply stores. Instead of sharpening the blades, most will opt to replace them.

 

A word of caution! These types of knives have short blades. Don't let this fool you, these blades are very dangerous and can cause serious, possibly fatal cuts. Use extreme caution when using a utility knife.

WARNING!! Utility Knife Blades are VERY SHARP. BE CAREFUL!!! WARNING!!!

There are basically two different types of utility knives. Ones with fixed blades and those with retractable blades. You will find several variations of both types. Some have slick features for easily replacing the blades. Others are supposed to be ergonomic. The cost can vary, but most of them run between $5 and $15.

Retractable utility knives have a button on them that slides the blade into the housing when the blade is not in use. This is both a safety feature and a preservation feature. The drawback to cutting drywall with a retractable blade is the quality of the retractable mechanism. You have to put a fair amount of pressure on the blade to cut into to or 'score' the drywall. Some of the cheaper utility knives will give way under the pressure.

A drywall utility knife with a fixed blades as the name implies does not retract. The blade is exposed at all times. This can be a safety issue. Use extreme caution when using a blade of this type. You also want to use a tool pouch that has a pocket designed for a utility knife. This will save the tool belt and your fingers from unwanted cuts. Most professional drywall hangers use a fixed blade. For a homeowner, it may be wiser to work with a retractable blade unless you experienced with a fixed blade. Be Careful with either kind of knife. Both will work fine as a drywall cutting tool.

Drywall Tee Square

drywall-cutting-tools-pic3Drywall comes in sheets that are four feet wide. Getting accurate cross cuts can be a little tricky and time consuming. For this purpose, the drywall 'tee square' was developed. It looks like a big tee, one side is four feet long and is used as a guide for the utility knife. The other side of the tee rests against the factory edge of the drywall, thus 'squaring' the cutting guide.

You hold the drywall tee square in place at the desired spot with your hand and toe (or knee). Using the utility knife, you follow the square, scoring the drywall. This speeds up the cutting process and increases the accuracy of the cuts. Drywall usually needs to butt up to other pieces of drywall, so a clean straight cut is important.

 

A drywall tee square is an important part of the drywall cutting tools line up. You can find them at stores that sell drywall and drywall supplies. A tee square will run around $15 or $20. Probably not worth it if you only have a couple of cuts to make. A bigger job or keeping it in your tool box for future projects will make it worth the investment.

Drywall and Sheetrock Saws

Keyhole Saw

drywall-cutting-tools-pic4A drywall keyhole saw is a small saw with a blade that comes to a point. The teeth are fairly coarse, making it an effective tool for cutting drywall.

The point can be used to bore into a sheet of drywall to cut out and opening, such as an electric box. It can also be uses to saw notches and other cuts in a sheet of drywall.

 

The drawback to cutting openings with a drywall keyhole saw is that you have to measure and lay them out on drywall. Then you cut them out before the drywall is installed. Getting accurate measurements requires some skill. Other cut outs, like pipes, have to be cut out ahead of time.

A keyhole saw is an important drywall cutting tool. Most of the time it is a must for a drywall repair project. A keyhole saw will cost between $5 and $10 and will generally last a long time.

Big Drywall Saw

big-drywall-saw-pic1In the days before routers, a big drywall saw was a standard item for a professional drywall hanger. It has heavy blade with large teeth. Originally they had wooden handles. Most of them today have plastic handles, making that a durable tool.

A big drywall saw is used to cut out large openings, like doors and windows, in the drywall. The design of the teeth keeps the saw from binding and will cut through drywall quickly.

 

You may want to consider this type of saw when you have a lot of cuts to make. For just a few cuts, a keyhole saw will work. A big drywall saw will run around $15. They are not as common as they once were, but they can still be found and drywall supply stores.

For most drywall hangers, the 'Drywall Router' has replaced the big drywall saw. Routers are also capable of making large cuts quickly.

Circle Cutter

drywall-circle-cutter-pic1When you have a round hole to cut, a drywall circle cutter is the tool of choice. A circle cutter is a compass of sorts. It has a center pin that is pushed into the drywall and a wheel that will score the paper. The wheel is attached to an adjustable shaft.

Pipes, light boxes and can lights, all require that round holes be cut into the drywall. Yes you can draw the circle on the drywall and cut them out with a keyhole saw. This tends to be a little time consuming and less accurate.

 

You set the diameter on the drywall circle cutter to match the size of hole you want. You still have to cut the hole out with a keyhole saw, the circle cutter just makes laying it out quicker and easier. It also scribes the paper on the drywall, giving the saw a path to follow.

A drywall circle cutter will cost about $15. They last a long time and would be considered a good investment for homeowners that are willing to tackle drywall projects. Most stores that sell drywall and drywall supplies will have this tool.

Drywall Router

drywall-cutting-tools-pic5Do you want to add some muscle to your drywall cutting tools? A drywall router would be just the thing. Routers have streamlined many of the cutting tasks for drywall. In addition, they have dramatically reduced the amount of lay out required to make cut outs.

The main advantage to a drywall router is that it will follow the item that needs to be cut out accurately and neatly. You tack the sheet of drywall in place and then insert the router inside the area to be cut out. You move to the outside of the cut out and then follow the shape with the router. No question, this if very cool!

 

There are some drawbacks. First, there is the router itself. It is not a standard router that you use for woodworking. It has a special sized collet for the drywall cutting bits. So there is the investment of $60 to $80 to consider. Second, they require some practice to use effectively. You need to learn which way to go to follow an opening. Additionally, you have to learn how to get to the outside edge of items like electric boxes.

Third, there is the mess. A drywall router creates a lot of dust. Drywall dust has the ability to get everywhere in a home very quickly. It is very fine dust and a chore to clean up. You can use a shop vac in conjunction with a router, but this is not a totally dust free solution and extra work.

For a small project, this type of drywall cutting tool does not make a lot of sense. When you have a bigger project or ongoing projects, you may want to consider it. Remember you will need to practice a little, before you start using it. See the article 'How To Cut Drywall', for some tips and tricks on using a drywall router.

Drywall Rasp

drywall-rasp-pic1A drywall rasp is used to smooth the edges of the drywall once a cut is made. You cut drywall by scoring the paper and then 'breaking' or 'snapping' it.

When you do this the gypsum core of the drywall breaks unevenly. The bumps in the gypsum can keep your panels from aligning properly.

 

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The solution to this problem is to smooth the edges. A drywall rasp will do the job nicely. It will cut the gypsum down until it is smooth with the edge of the paper.

A rasp is inexpensive, around $5 to $10. This can be a good addition to your drywall cutting tools.

Stanley makes a rasp that is commonly available and sells for under ten dollars. Wal-Board makes one that is used by professionals that is available most places that drywall is sold.

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