Included in the package is a collapsible spring that is inserted into the front of the plate, then compressed with your fingers. The plate is then placed to block the vent with the spring set (as the directions explain), then inserted into the center hole in the existing foundation vent screen. The next step is to release the spring; presto, the vent cover is installed. The instructions are included on the package card.
Approximately 1". If you have any other inquiries about our Master Flow products please call Technical Services at 800-211-9612.
I installed 6-vent covers, they worked great , took me 1/2-hr. to install all.
No. While not an "airtight" seal, they will certainly not allow any air "flow".
In the hot humid south, you don't want warm humid outside air to enter the crawl space and add moisture under you house. Many of us need a vapor barrier over the dirt in the crawl space to keep the moisture from coming up from the soil and it is bad for the moisture to enter into the crawl space through the vents. The warm humid air from outside cools under the air conditioned house and the air becomes more saturated and increases the moisture under the house and in the wood floor joists increasing mold and rot. From a moisture perspective, the moisture is so low in the cold months (winter) that keeping the vents closed is fine unless you need to vent something such as radon gas, etc. If you need to vent to get rid of radon or other gases or smells, you need an engineered plan with active components such as fans and / or dehumidifiers. In the hot humid south, it is better to keep the vents closed to reduce mold and rot.
spring stays on the outside but if your slide for the vent is in the middle the springs won't work I drilled a 1/8 inch hole and screwed them on
towards the yard
It would depend on the diameter of the hole in the block.
Yes, they are easily removed and replaced but be aware that the metal is very thin and easily deformed. Take care when removing and replacing