There are plenty of ways to connect PVC piping, but it’s important to learn which method works best for you. Depending on the method you choose, you can create a temporary connection or literally bond the PVC pipe together.
Suitable connection methods differ depending on your project and what you have at hand. In this article, we look at the basics of making a durable connection, how fittings enhance your connection, and different ways to join PVC pipes.
Useful Tools to Connect PVC Piping
When connecting PVC piping, make sure you have basic tools for dealing with piping on hand. This includes:
- A pipe cutter (or a suitable saw for cutting pipe)
- Sandpaper or a utility knife (for dealing with post-cut burrs)
- A marker (to mark joints)
- Rags (for cleaning drips or spills)
- Extra pipe
- Your connecting method of choice
Make sure you have a basic understanding of what connections you need to make and what work they must hold up against.
Tips and Safety for Connecting PVC Piping
It’s a good idea to have extra pipe and fittings on hand in case you make a mistake when cutting your pipe or making your connections. This is especially important with more permanent methods, such as solvents.
Clean your PVC before making your connection, even with push-on or threaded connections. A PVC cleaner works well for dirt, dust, and grime, and 80-grit sandpaper can rid the pipe of burrs that cause clogs and interfere with tight connections.
If you’re using solvents, make sure you protect your skin and work area. Ventilate the space as much as possible, and wear protective gear such as a ventilator, safety goggles, and gloves.
PVC Fittings Basics
PVC fittings are used to connect pieces of pipe together. There are several types that allow you to do things, such as:
- Attach two pipes to create one longer pipe
- Change the direction of your PVC
- Make quick connections
PVC fittings come in standard sizes that fit snugly around your PVC, and you must choose the right diameter for an effective connection. While PVC fittings can hold your pipe in place, the pipe joint on its own is not water safe.
Furniture Grade vs. Regular PVC Fittings
Like PVC pipe, fittings come in furniture grade and standard varieties.
Furniture-grade PVC is more resistant to sun damage and degradation, therefore less likely to change when exposed to UV radiation. It’s also more impact resistant, and there are no markings on the fittings’ exterior.
If you’re connecting PVC that will be exposed or sit outside, choose furniture-grade fittings.
Types of PVC Fittings
There are many varieties of fittings that offer different types of connections and allow you to achieve different angles with your PVC.
Some of the most common include:
- Adapters: also known as reducing couplings; change the end type of PVC pipe so it fits different sizes and types of PVC
- Bushings: usually threaded; mainly used to connect PVC pipes with different connectors via reduction
- Caps and Plugs: stop the flow in a pipe (caps at the end of pipe and plugs inside other fittings); plugs usually have as a spigot or a male threaded end
- Couplings: connect two pipes together in a straight line; some reduce to connect small and large pipes
- Crosses: form a “plus”; useful when creating framework
- Elbows: come in different angles; allow you to direct pipe around objects; side elbows have three ends to create corners
- Flanges: allow you to connect PVC to items other than PVC (i.e. the base of a toilet); resemble a disc and create a seal between the object and the PVC
- Nipples: fitting with two male-threaded ends used to connect two female-threaded ends
- Unions: not as permanent as couplings; feature a ring for easy deconstruction; often used in temporary builds
- Tees: shaped like a “T” with a two ends in a straight line and a third at the side; allow you to split a line into two with a perpendicular connection (or connect two into one)
Most PVC connections use a fitting in some way. Your fitting and the intended use of your project affect the method you use to connect your PVC pipe.
Methods to Connect PVC Piping
The most common and effective methods to connect PVC piping include:
- Dry fitting
- Silicone or glue
- PVC solvents
- Flex couplings
- Push on fittings
- Threaded PVC connections
The first 4 work with standard fittings, but you need special fitting styles for the last 3 methods. Because some methods do not create a watertight seal, it’s important to choose the right method for your project.
1. Dry Fitting
Dry fitting is the simplest way to connect PVC pipe, but you shouldn’t rely on it as a permanent solution. To do this, simply push your PVC pipe into your fitting.
While PVC pipe sits snugly in appropriately sized fittings, a dry fit will back out over time, especially when under pressure.
We recommend you dry fit your PVC prior to more permanent connection methods and label your connections. This is often your last opportunity to make quick and easy corrections.
Another temporary connection method involves the use of fasteners, such as screws. This is nowhere near as strong as other methods, and it damages the integrity of your PVC, but fasteners allow you to connect PVC with little fuss.
To do this, dry fit your material as tightly as possible. Use an appropriate drill bit to make a pilot in your PVC and fitting, then run a self-tapping screw into this pilot hole.
The screw will hold everything together, but this connection method runs a higher risk of coming apart over time.
3. Silicone and Glue
Regular adhesives, such as silicone and glue, hold up well with low-impact projects, but they may still back out over time. You cannot use silicone or glue to hold connections that transport water or vapors.
If you plan on using silicone or glue to connect PVC pipe, use a PVC cleaner on the inside of your fitting and the outside of your pipe first. You may also want to rough up the connecting surfaces with sandpaper to enhance the connection.
Apply the glue to one surface, then fit the PVC pipe into the fitting. Hold it in place long enough to let the adhesive set for the recommended time (preferably longer).
Silicone or glue is still likely to back out over time, but combining it with the fastener method may help. For more permanent connections and less fuss, consider using a specialized solvent to connect your PVC.
4. PVC Solvents/ PVC Cement
Most connections require a PVC solvent (such as PVC glue or PVC cement) that melts the surface of the pipe and the fitting to join the pieces together permanently. If you plan on connecting PVC for plumbing, this is what you need.
Make sure you remove any burrs prior to using a PVC solvent. They can cause clogs in drain lines and interfere with the connection on the outside, and you cannot simply try again if burrs cause the connection to fail.
Brush over your surface with a PVC primer before going in with your solvent. The primer cleans your pvc, softens the surface, and serves as a visual indicator of its use (for inspection purposes).
Apply the solvent, then insert your PVC pipe into the fitting. Turn the pipe slightly, then hold it inside the fitting for at least 15 seconds to prevent it from backing out.
Allow at least 20 minutes for the solvent to cure before further handling.
5. Flex Couplings
Flexible couplings, such as those by Fernco, allow you to connect PVC pipe without permanently welding pieces together. These aren’t approved for all applications, but flexible couplings create effective seals and strong holds.
Flexible couplings use strong steel band clamps to hold the rubber tight around your PVC pipe.
To make the connection, insert your PVC pipe into the flex coupling and seat it firmly. Tighten the clamp to create a seal and prevent the pipe from backing out.
6. Push-On Fittings for PVC
Push-on fittings are a special type of connector that prevent the need for adhesive or welding. Instead, they feature a ring with spurs on the inside that enhance the connection.
This is a permanent type of connection. Once you insert PVC inside of the fitting, you’ll need a saw to separate the parts.
Push-on fittings are a great choice for quick repairs in certain systems. They have an o-ring to create a watertight seal, and you can use them in most concealed applications.
This usually comes down to what you’re comfortable using to connect PVC for your project.
7. Threaded PVC Pipes
Threaded PVC pipes and fittings are another option for those who don’t want to deal with solvents or permanent connections.
Threaded connections have lower pressure ratings and a greater reputation for failing. Joining threaded PVC properly is essential for strong connections.
Clean your PVC pipe and fitting with a strong PVC cleaner, then apply a PVC thread sealant specially designed for this purpose. Once applied, insert the pipe into your fighting and turn until there is no more give.
You can use a wrench to further the connection, but make sure not to over tighten. This may cause cracks that lead to leaks.
Make sure you use a connection method that suits your project and experience. When possible, focus on more permanent methods to create strong connections.
- Dry fit your pipe before making permanent decisions
- Clear burrs and clean your PVC
- Follow instructions specific to the materials you use
Comment below with any questions, tips, or tricks you have about connecting PVC piping!