What is a Raked Mortar Joint?
A raked mortar joint is when the top layer of mortar (the “top” part) is laid down flat against the bottom layer of mortar (the “bottom” part). A raked mortared joint will give better results than a flush or beaded one.
For example, if you were trying to make a fence with the following:
1. Two boards of wood are cut to length.
2. One board is placed on top of another and the two boards are glued together.
3. The top board is then covered with gravel and sand so it doesn’t scratch your furniture during use.
4. You want to make sure the top board isn’t going to fall off while you work on other parts of the fence.
5. How would you go about doing this? Would you glue the boards together first, lay them out flat, and then cover them with gravel and sand? Or would you do something else entirely?
The answer is probably some combination of all three! If you have any experience using either type of mortar joint, please share your thoughts in the comments section below.
5. How would you go about finishing the joint? Would you lay down the top board flat against the bottom board? Or would you leave some space between them so they don’t touch each other at all?
The answer is that both options have their advantages and disadvantages. Let’s take a look at each option:
Option 1: Lay Down Top Board Flat Against Bottom Board!
You decide to lay down the top board flat against the bottom board. This way, you can place the sand and gravel on top of the wood so everything is even and there are no spaces between them.
The only issue with this approach is that the sand will fall through the spaces between the boards, or get stuck in between them!
This is a very common mistake that people make when using this type of joint. The top board doesn’t actually do its intended job, instead the bottom board does it!
So, you have to put down more sand and gravel on top of both boards before putting them to use.
A lot of people attempt to prevent this issue by “scuffing up” the bottom board. This is a time-consuming process that can drive you a little crazy (especially if you’re using a saw with a dull blade).
Option 2: Leave Some Space Between the Boards!
I usually use this option when joining wood for one of three reasons. The first is that the wood didn’t fit together properly, the second is that I was in a rush when I got to this point in the process, and the third is due to laziness.
If you do decide to leave some space between the boards, I would recommend placing some small strips of wood around the outside edges of the bottom board. These strips of wood can then act as a barrier between the sand and gravel you pour in, and the parts of the wood that don’t really need any sand or gravel under them.
By doing this, you can be sure that only the needed parts are getting covered. It also helps if your saw blade is dull so that the spaces between the boards are wider than you intended.
This way, less sand and gravel will fall through the spaces.
Now that you have a basic understanding of the different types of joints used to join wood, I can explain the different types of fastening systems available to you.
The type of fastening system you use is important because it affects how much space you have to work with when laying down the sand and gravel. Some people prefer not to cover the edges of their lumber at all, while others insist that the wood be fully covered on all sides (my opinion).
The three most basic types of fastenings are:
There are many different types of bolts, but I won’t go into too much detail about them in this post. The rest of this post will focus on nails and screws since these are the two items that people have the most questions about.
I would recommend using nails over screws since they tend to work better with the type of joints being used. Also, sand and gravel get stuck in the threads of screws more often than you might expect.
This can be prevented with the use of a nylon-coated screw (the plastic coating prevents the sand and gravel from getting caught in the thread), but some people don’t like to use these for aesthetic reasons.
Nails are very simple to use because they require minimal effort and only a hammer is required to install them. This can be good or bad depending on how strong you are, and how accurate you are with the hammer.
Negative aspects of using nails:
They have a tendency to bend if they go into hard wood, like oak. The more you drive them in, the more likely they are to bend.
This means that, if you happen to hit a knot in the wood, the nail will most likely snap in two.
If you don’t hit the board at the right angle, the nails will often times slide off to the side and not go in as far as you wanted it to. This can be really frustrating when nailing down plywood because it will cause the boards to buckle from lack of support.
If you are using too small of a hammer, your fingers will get tired really fast.
Some people don’t like the look of unfinished wood (sanding the heads off can be a real pain). Not everyone has a nail set though, so this might not matter to some people.
To make nailing even easier:
Use a nail set after you’ve hammered in the nail close to the board. This will drive the nail below the surface and prevent it from catching on things.
This tool also makes it easier to sink the nail below the surface with just a few light taps of a hammer.
There are several different types of nails. I’ll just go over the different types I use the most:
Grain (not to be confused with galvanized) nails are great for installing plywood, especially if you don’t have a nail gun. Since grain is going vertical with plywood, the nails are more likely to hold in place without bending.
Even if they do bend, it’s not as visible. These are harder to find nowadays, but you might be able to find them at an old-fashioned hardware store.
Common nails are the most common type of nail that you see everywhere. They are good for just about everything, but I don’t use them as much since I like to use other types for certain applications.
Flathead nails have a flat head (duh), which means that they don’t protrude as far from the board when installed. This makes them great for concealing the nail if you are putting an image over the top of it (like in picture frames or shadow-boxes).
Spike nails are similar to common nails, but have a larger diameter and a slightly different shape. I use these mostly for pallet projects due to the larger head which seems to hold better with the softer wood (often times pallets are soaked from being outdoors and the wood tends to deform slightly when you drive in a nail).
I’ve found that with these, I don’t get the splitting or breaking that I do with common nails.
2. A Nail Set
A nail set looks like a small hammer and is used to set the nail below the wood surface, making it less likely to snag on things (and also preventing it from wiggling loose over time). This tool can also be used to sink the nail head below the surface of the wood if you don’t happen to have a nail set handy.
If you don’t have a hammer or a nail set and want to sink the nail below the surface, you can use the handle of your screwdriver (or some other small, heavy object). While this isn’t as effective as a proper nail set, it will work to prevent snagging.
Many people don’t know that you should NEVER use your fingers to set a nail. You can seriously hurt your fingers (or even lose one) if the nail set slips.
ALWAYS use a piece of wood or something else to set the nail below the surface to prevent injury.
3. A Nail Puller
Nail pullers are designed to grab the head of the nail and just…well…pull it out (obviously, you can guess what this tool is designed for).
Most of these have different types of teeth that can grab the nail head. For example, there are smooth teeth, normal teeth, and even serrated teeth. Some are even designed to grab the little “tails” of screws.
I have a small smooth-tooth nail puller that fits in my tool kit. I mainly only use it to pull out nails that I didn’t drive in completely.
Over time, the heads will begin to bend and deform, so I’ll pull them out with my nail puller rather than ruining a perfectly good nail by driving it in further.
4. A Nail Set Hammer
So similar to the nail set, except this one is designed to be hit with a hammer. Just place it over the top of the nail (make sure you place it straight or you will miss the head of the nail), and whack it with your hammer.
This is the fastest way to sink a nail below the wood surface.
5. Other Nail-Related Things
There are a few other things related to nails that I use in my shop on a regular basis. These aren’t required for your tool kit, but if you have room, they are nice to have around.
A Nail Chuck makes it much easier to change out the nails in your nail gun. You simply open it up and stick a new one in.
This saves a bunch of time reloading your gun every 5 minutes.
A Magnetic Nail Holder is another great time-saver. Rather than trying to pick up nails off the ground, you can simply place this on top of the nail AND the wood (so it stays in place) and then reload your gun.
When you are done nailing, you can just pull this off the wood and all of the nails will be held securely in the magnet.
You probably don’t want to keep your gun and air hose inside your vehicle while using it. It gets pretty cold in the winter, and if you are using your gun for any extended period of time, the interior of your car will quickly warm up.
Wet air hoses can freeze, so make sure to keep them in the house where it is warmer, or at least wrap them up so they don’t freeze (I actually have a special thermal cover I keep on my air hose).
If you happen to live in a particularly warm climate and find that your hose freezes up anyway, you can always use an Air Chuck. This keeps the hose from freezing by taking the air from outside.
It is like a connector that attaches to your hose and one that you just stick out the window and let it suck in air from outside. I keep one of these on my house’s outside air hose that I use for painting, so I don’t have to worry about it freezing up.
Wear Gloves and Eye Protection
I know this should probably be #1 on the list, but gloves and eye protection should really be worn at all times in the shop. However, I still see people without them on every day.
Most shops require them, and for good reason! So don’t forget them!
Here is a quick rundown of the different types that you will find in most shops:
These are the standard eye protection that you always see in shops. They cover most of your eyes, except for a space to see out of.
Most of them are just plain plastic, but some of the fancier types have some sort of ventilation system to prevent them from fogging up. These are good general purpose safety glasses, but they do not protect your eyes from everything.
Metal Shavings or small pieces of wood can sometimes shoot out with enough force to break through the plastic and potentially hit you in the eye. Also, if you are working around a bunch of chemicals or dealing with particularly nasty spills you will find that these do not offer the best eye protection.
Metal & Wood Debris
These are glasses that wrap around your entire eye area and usually have a vent on the side to allow air in (so they don’t fog up). These are good for when you are doing a lot of work with particularly nasty chemicals or waxes.
You can also wear these when you are doing fine detailed work where there is a potential for small pieces of wood or metal to fly at your eyes.
These do not cover your entire face, so if you are worried about things falling down on you or you are working in a particularly large area (like a mill) then you should probably wear some sort of full face protection.
Full Face Protection
These include things like welding masks and ski goggles. They cover everything except your mouth and are good for when you are working in particularly large or open areas like a mill.
If you are welding, then you will also need to wear a helmet as well.
Most of these also come with a variety of interchangeable filters. The most common ones you will find in our industry are:
1. Clear (Off-White) – this is for general use and doesn’t provide any UV protection.
2. Dark Green – this is for welding as it allows only a minimal amount of UV light to pass.
3. Light Green – this is for grinding and abrasive work such as sanding, as it reduces the amount of light produced from the spark.
4. Red – this is also for welding but creates a bulls-eye effect, making the center of the flame orange while producing a red hue around the outside of the flame.
Try not to actually look directly at the flame!
5. Amber – this is for when you are cutting as it produces a larger amount of carbon dioxide and reduces the amount of oxygen in the flame, creating a less reactive environment.
6. Blue – this is used when soldering as it creates the optimum temperature for the solder to flow properly.
This includes Masks with or without a Respirator built into them.
These protect your entire face from airborne debris and chemicals. They also cover your mouth, so if you are working in a dusty area you can breath through that instead of your nose (which will minimize the amount of dust that gets up there).
They come in several different forms and levels or protection. They can range from the cheap paper type, to facemasks with varying levels of filters.
The cheaper versions will not protect for long when dealing with serious chemicals or airborne diseases. The mid-range can be used for serious biological contaminants (such as bird flu) but will not protect from anything caustic or especially noxious.
The best types will block almost everything, but can be quite pricey.
They come in two main forms:
Foam Pre-Molded – these sit directly over your mouth and nose, they can be shaped to fit around a normal face or pressed against a protective shield of some sort.
Sources & references used in this article:
- Durability of block work: the effect of varying water/cement ratio of mortar joint (TC Nwofor – Pelagia Research Library, Advances in Applied …, 2012 – researchgate.net)
- Stone fabrication system with hidden mortar joint (DA Brown, R Brown – US Patent 9,388,571, 2016 – Google Patents)
- Ceiling finish joint for dry wall partitions and method of making same (FE Groshong – US Patent 4,598,516, 1986 – Google Patents)
- Brick-mason’s joint raker and smoother. (FH Ackerson – US Patent 1,292,558, 1919 – Google Patents)
- Mortar joint finishing tool (CH Hazelrigg – US Patent 3,403,419, 1968 – Google Patents)
- Mortar joint simulator tool (RO Billings – US Patent 2,945,253, 1960 – Google Patents)
- Finish for walls (P Louis – US Patent 2,162,861, 1939 – Google Patents)
- RILEM TC 203-RHM: Repair mortars for historic masonry: Requirements for repointing mortars for historic masonry (TC 203-RHM (Main author: Paul Maurenbrecher) … – Materials and …, 2012 – Springer)
- An investigation of factors affecting the durability of masonry mortar (SJ Lawrence, T Testone, HO Sugo, A Page – 2008 – hms.civil.uminho.pt)