You already know how easy it is to build with PVC pipe, but there is one crucial step to making sure that your structure is strong and secure - connecting everything together, which is just as easy.

There are two ways for connecting PVC pipe and fittings together for a structural project.  They are the PVC solvent (cement) method, and the fastener connect technique.  Both versions work well, but we ALWAYS recommend using PVC cement, as it is the most secure and permanent answer.

Connecting PVC Pipe and Fittings via PVC Solvents

Attaching PVC pipe to fittings with PVC cement is not ‘gluing’ them together, it is in fact welding them together.  The PVC cement melts the surfaces of the plastics, and after about 30 seconds, permanently fuses them together.  This is excellent, because now all of your PVC elements are essential one giant, fused structure, making them just that much more stronger as one solid unit.  Here is how to connect PVC together with PVC cement:

For External Fittings

  1. Double check how you want items to be connected (angles, direction, etc.).  Its a good idea to do a test-fit first, to make sure everything fits together like you want it.
  2. Make sure both the pipe and fitting are clean of any dust or dirt.  This is especially true if using plumbing PVC pipe.
  3. Apply a small amount of PVC cement to the inside of the fitting where the ‘stop’ or detent is.  The stop is the small lip inside of the fitting where the pipe is finally seated.
  4. Insert the pipe all the way into the fitting and hold for 30 seconds.  Use a mallet or piece of wood to tap the pipe into place, if it will not insert fully by hand.

For Dome Caps and Couplings

  1. Perform steps 1-2 as shown above.
  2. Apply a small amount of PVC cement to the inside of the PVC pipe.  Do not apply any PVC cement to the end of the coupling or dome cap.
  3. Insert the coupling or cap into the pipe.  Use a mallet or piece of wood to tap the cap or coupling into place, if it will not insert fully by hand.  Allow 30 seconds to cure.

Connecting PVC pipe and Fittings via Fasteners

You can temporarily, yet securely, attach PVC pipe and fittings together using fasteners (screws) to give a strong structural hold, without the permanent connection of PVC cement.  This allows you to reuse or reposition the fittings later.  This is a great method to connect PVC, but has some limitations:  it’s not as strong as PVC cement and wont work for internal-fit components such as couplings and dome caps.  Here is how to connect PVC together with fasteners:

  1. Insert the pipe into the fitting.  Make sure that it is fully seated and use a mallet if necessary to make sure it is completely inserted.
  2. Use a 1/8” drill bill to make a pilot hole about midway where the pipe and fitting meet, into the side of the fitting.  This will make it easier to insert the screw.
  3. Using a power drill or driver, insert a self-tapping, threaded screw into the pilot hole you just drilled.  Make sure that the screw is long enough to go through the fitting and pipe.

Conclusion

Both the methods outlines above will work to make your PVC structure sound and strong and give them a lifetime of use.  If neither of the methods above sound like something you wish to do, you can push pipe and fittings together, and in many cases they will remain connected, however due to variances in manufacturing, you may end up with pieces that are too loose.  If this is the case, we recommend that you at least use the fastener connection technique to join any loose elements.