Most of the vanities for the bathroom come with cabinets or drawers to place different products and daily use things at an accessible distance. However, there can be some issues with installing the P-traps for such vanities because the drawers can interrupt the plumbing system under the sink base.
How to Install P-Trap For Vanity With Drawers? You can install a P-trap for a vanity with drawers by gathering all essential tools, cutting a rectangular hole in the drawer, applying sealant around the cut, and installing the P-trap with proper space. In addition, you can use other alternatives, such as cutting the drywall, selecting built-in P-trap drawers, selecting shorter p-traps, or using other types of traps.
The P-traps under the sink need proper installation and space, and you have to select vanities with cabinets for this place that can accommodate all necessary plumbing systems. I recently bought a new vanity for my bathroom while renovating the interior and faced plumbing issues, especially for the P-trap.
How can you install P-Trap for a vanity with drawers?
You can install it for the vanity with drawers following the steps explained below without damaging the vanity and the drawers and their functionality.
Gather all essential tools
You need to collect all necessary tools for this project, such as a pencil, saw, waterproof sealant, measuring tape, glue, and abrasive paper.
Most vanities in the bathroom come with two or three drawers, and you can select large vanity, depending on the bathroom size where you want to install this vanity.
Select high-quality products to avoid leakages, and measure the length of this trap from the sink base to the drawer before cutting the drawer or the wall.
Cut a rectangular hole in the drawer
Install the P-trap at its position and mark the area on the drawer, and you have to cut it using a pencil or a marker. Make sure to install it accurately to avoid the wrong measurement for a cut in the drawer so that the trap can fit properly in this place.
A wrong cut can cause problems when you open the cabinet and affects the proper use of the vanity to store different products.
Now remove the P trap and remove the drawer from the vanity to cut a hole in the marked position. Cut the marked rectangular area using a saw and smooth the edges around the hole using abrasive paper or sandpaper.
Apply sealant around the cut
It can leak when the sink base has cracks if you drop a heavy object on its surface, and the water can seep into the drawer through the damaged plumbing fixture.
The drawers made using wood can warp if exposed to moisture; therefore, professional plumbers recommend applying a waterproof sealant on the edges of the rectangular cut.
You can use a caulk gun and smoothen it using your fingertips to avoid contact with the vanity or other components.
You can cut a rectangular shape piece to join and fix around the cut and make separate portions to place the daily-use products.
Install the P-trap
Now, install it correctly while securing all the necessary connections, and make sure that the sink drain pipe is lined up with the trap properly.
You can cut the pipes if it does not fit under the sink drain and use glue to attach all the parts, such as the trap arm, washer, and U bend.
Test the drawer and P-trap functioning
Now, place the drawer back in the vanity and check its functioning by opening and closing the drawer 2 to 3 times.
Turn the water supply on and check whether the P trap is installed correctly and if there are no leakages in it.
You can reinstall it and take the necessary steps to set the cut if the plumbing pipes interrupt the drawer. However, it causes corrections in the rectangular cutting in the drawer and needs extra hard work and time. Therefore, measure the correct size for a cut to avoid problems afterward.
What are the other ways to fit the P trap for vanity with drawers?
There are some other ways to add the P-trap for vanity, and these techniques are explained below.
Cut the drywall
You can cut the drywall horizontally or vertically depending on the placement or the size of the P-trap to allow enough space for proper installation if you have a vanity with cabinets.
The process is tricky and needs special skills and experience because cutting the drywall with correct measurements is difficult.
However, cutting a concrete wall is difficult and can create a lot of mess around the vanity area, but it can allow some extra inches for the plumbing pipes to adjust.
Select the drawers with build-in P-trap space
Modern vanities come with the built-in P-trap space in the upper drawer or behind the cabinet to install all the plumbing systems require for the sink.
You can select different colors, materials, and ranges for these vanities to solve the P-trap adjusting problem. They come with single and double vanities, and the cost can vary for large vanity and cabinet options.
Choose a shorter trap
Choosing a shorter or shallow P-trap can solve the problem of fitting it in the vanity with drawers, and it needs the correct measurement of the distance between the sink drain and the lowest trap portion.
According to the Universal Plumbing Code, this distance can be 24 inches maximum, and UPC requires no minimum distance between the sink drain and the P-trap.
Therefore, you can select a shorter trap that can adjust with the drawers and take a tailpiece to connect the shorter end with the sink drain outlet.
They come in different sizes, such as with 2 to 4 inches depth, and you can select a shorter and shallow one because the building codes can allow a shorter arm and trap length for authentic reasons.
Get other types of traps (waterless or S traps)
You can use other trap types if you have a small house or live in an RV. People use waterless traps or HepvO valves as an alternative to the P-trap.
HepvO valve can work well by controlling the sewer gases from rising in the sink and allowing water to flow into the drain. It uses the valves to open the drains for wastewater flow and close them afterward to prevent toxic gases into the bathroom.
They are also a good option for vanity with drawers when you do not want to cut the wall or vanity to install the plumbing system there.
Does double vanity need two P-traps?
A double vanity does not need two separate P-traps for the proper water flow, as you can connect the two sink drains with a tee and feed the tee into the single P-trap.
The pipes that connect the two sinks have a slip-joint connector, and you can easily tighten it or cut it as required to fit the double vanity plumbing system.
The tailpiece of the two sinks must have the same length when you connect them to the single trap. It requires proper knowledge and experience to install the double vanity sinks with the single P-trap because it can cause leakage problems if you do not secure all the connections and fittings properly.
You can also use two traps for the double vanity and two separate sinks to better work the drainage system and water flow. This is beneficial when you have two drains for two sinks, but the single drain can work well with a single P-trap.
What happens if you do not use a P-trap for vanity with drawers?
Installing it under the vanity is essential, whether you have drawers or not because it can affect the functioning of the drainage system, and it is against building regulations.
They are necessary to prevent the toxic gases in the sewage pipes from entering the bathroom and affecting your health. Moreover, improper water flow can cause clogging in the drain pipes if you do not use these traps.
You can use an S trap if the vanity has depth and you do not find enough space for the P-trap to fit because of the cabinets and the drawers.
You can install different sizes of traps or cut the pipes into the required sizes to adjust them with the drawers.