You need a good grade of caulking with a long guarantee on it.
Caulk underneath gutters.
Caulk is a necessary part of gutter maintenance.
If your gutter has been previously installed rather than taking it down and redoing it you can easily place a small strip of metal flashing under the drip edge and over the back of the gutter as shown by the illustration at the bottom of this page so the water will shed into the gutter.
Choose either white silicone caulk or a clear caulk if your gutters are a different color.
Use your finger to smooth the caulk into a strip.
Caulking may be painted if you are going to paint your gutters.
How to use it.
We understand this is a lot of work and is quite dangerous however it can be completed successfully by following the tips in this article.
Simply cut the tip of the caulk at an angle put the caulk tube into a caulk gun and apply in a straight small bead.
Latex caulk and silicone sealant typically dry to the touch within 30 minutes but they can take up to 24 hours to completely cure and be fully waterproof.
Allow 24 48 hours dry time yes avoid any rainy days in the forecast and you should be good to go.
The caulk adheres quickly and as it cures it remains flexible.
Professionally installed gutters should have been caulked already but caulk will need to be replaced every decade or so.
Simply squeeze into cracks and holes then apply a further coating around the entire gutter joint.
Use a commercial grade gutter sealant and simply re apply where needed in a thorough manner.
A waterproof sealing product such as ge clear gutter caulk available on amazon is easy to use.
The seams of your rain gutters can rust if left unprotected and fungi can begin to grow in the seams if rotted leaves or other organic matter gets caught in the cracks.
Be sure it is for water use.
Apply a generous amount of gutter sealant around the male end joint and around all rivets using a caulk gun and then attach to the female end of the joint.
Butyl rubber caulks marketed by dap as their butyl flex line is an excellent choice for repairing leaky gutters.
Fast drying formulas can cure in under 24 hours depending on the temperature and humidity.