If you find water in the cabinet below your kitchen faucet sink, it could come from a faucet base plate leak.
Of course, it could also come from the supply lines or the drain. But since we’ve solved those issues in previous articles, let’s review how to seal the base plate.
How to Fix a Leaky Faucet Base Plate
If neither the supply line nor drain is your issue, then there’s a good chance your kitchen faucet base plate is leaking. Here’s what you’ll need:
- 2 hours to remove, seal, and replace the faucet if you need to go through all 4 steps below. Less time if you don’t.
- Basic plumbing skills
- Putty knife
- Groove-joint pliers or basin wrench (about $14 at Home Depot and worth every penny!)
1. Tighten the Mounting Nuts
It might be that your faucet is not held tightly against the sink. If that’s the case, then follow these instructions:
- Get under your sink in as comfortable a position as possible and tighten the mounting nuts.
- If you can’t turn them with pliers, use a basin wrench.
- If this doesn’t solve the problem, move on to Step #2 below.
2. Loosen & Stuff with Putty
- First, try to fix the leak without removing the faucet.
- Loosen the mounting nuts enough to raise the fauce base about 1/2 inch above the sink.
- Scrape out any hardened old putty.
- Holding the base plate just above the sink, stuff plumber’s putty under it evenly.
- Retighten the mounting nuts.
- If it continues to leak, proceed to Step #3 below.
3. Remove the Faucet & Scrape
- Shut off the water and drain the line.
- To entirely reseat the base plate, remove the faucet.
- Disconnect the supply lines, remove the mounting nuts, and pull out the faucet.
- Scrape any old putty away and clean the area thoroughly.
- Take care not to scratch the sink.
4. Replace the Gasket or Apply New Putty
- If the faucet has a gasket (a rubber seal or washer), throw it out and replace it with a new one (you can get these at any hardware store).
- If you have trouble finding a replacement, purchase a piece of rubber of a similar thickness and make your own gasket. Just use the old gasket as a patter to cut out a new one.
- Many plumbers believe putty lasts longer than gaskets, so even if your faucet has a gasket, you might want to discard it and apply putty instead.
- Roll a rope of putty about 1/4 inch in diameter and apply it to the sink or to the underside of the faucet.
- Reinstall the faucet with base plate and check for leaks.
These instructions are building blocks. If the first step doesn’t fix the leaking kitchen faucet base plate, then move on to Step #2, and so forth. You’ll probably find that the leak doesn’t require you to go through all four steps before fixing the problem. But even if so, you have everything you need here to get it done!
- How to use plumber’s putty (with video!)
- Is your ceramic disc faucet leaking?
- Leaky faucet troubleshooting guide
- Why is my faucet leaking (5 real possibilities)
- 3 ways to fix a faucet leaking from its stem
- How to clean a faucet aerator (with video!)
- How to unclog a kitchen sink sprayer
- Everything you need to know about kitchen sink plumbing
- How much does it cost to install a sink faucet?
- Tips on choosing a new faucet (with checklist)
1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.