This could be caused by humidity in the roof that is not able to escape.
New roof leaking at the ridge vent.
You need to repair the problem immediately by replacing or re screwing the ridge vent to the roof.
You should inspect your ridge vent annually.
Sun exposure and heat especially during the summer can cause the rubber boot to crack creating the space for water to leak in.
This happens because of the change in air pressure.
No you should not need to replace your ridge vent when replacing your roofing tiles if your ridge vent is still in good working order.
The rain will eventually make its way into the attic.
Installers may use the wrong nails to attach the vent to the roof which allows it to loosen and be pulled off in high winds.
Shingles cover the area where the ridge vent is fastened down.
When the roof vent is leaking the actual cause must be identified first.
A bead of sealant should continuously run along the sections of the vent.
If the fasteners are not secure a strong wind may pull up the ridge cap and let rain or snow get into the vent causing it to leak.
Check your soffit vents and ridge vents for any visible blockages.
Another problem that can lead to leaking roof ridge vents involves sealant.
Typically ridge vents do not leak.
Slightly pull the ridge vent upward and look for the fasteners.
When your roof was installed each vent pipe received a flexible boot to seal water around the round surface of the vent pipe.
If you find any that are loose or if your ridge vent seems to easily disconnect itself from the roof.
Repairing leaking ridge vents.
Vent pipe leaks during heavy rain can occur if you have cracks in your vent pipe boot or flashing.
These boots vary in quality flexibility and longevity.
You should be able to see the top of them.
It is possible to remove the ridge vent safely have the work done to your roofing tiles and then fit your old ridge vent back in place.
When looking for a potential ridge vent leak go along the entire length of your ridge vent.
Other causes of leaking roof vent are including broken seams on the metal base loosen nails and rusty metal collars around the vent pipe.
While you are on the roof walk along the entire length of the ridge vent.
You can then draw fresh air into the underside of the vent which freshens the environment of the home.
The inside air moves through the ridge vest underneath the cap shingle to escape from the side and into the general atmosphere.