Do you to block a unwanted 4 inch hole or reuse it for something else?

Question

Have 4 inch hole was made by builder for no reason and went unnoticed for long time as the hole was in the side wall of the House. the hole is through a basement wall.

How can I permanently block the whole. I am ok to keep vent mounting block as is. so can I just block the hole from inside by a plywood ?

I don't have any requirement to reuse the hole unless I am aware of.

Thanks!

Answer 1

Yes, you can cover it up with plywood. However:

was made by builder for no reason

No, it was for a reason. If it was for no reason, they would have likely just covered it with regular siding. When they went to the extra effort of a proper cover, that's an indication they really intended to make the hole. You just don't know what that reason is. Typically, this would be a vent for a dryer, cooktop or bathroom exhaust. Either there is something typically included in the house that wasn't included here, something that was removed or something that was never installed (that should have been installed).

A plywood cover with a few screws is easy enough to remove if you later figure it out. But consider all of the following:

• Do you have a clothes dryer? Is it vented? Is it possible that some owners put it in one location and some put it in a different location?
• Kitchen cooktop - Does it currently have a fan? If not, is this close enough that it could be used for an exhaust fan?
• Bathrooms - Bathrooms generally require a fan except if they have an operable window of a certain minimum size (specified in the building code). Is there a bathroom near this location that doesn't have a fan but should? Or that doesn't have a fan because it has a window but could have a fan connected here?

Answer 2

Have 4 inch hole was made by builder for no reason

There is a reason; even if that reason is simply "by accident".

went unnoticed for long time as the hole was in the side wall of the house

How long is a "long time" exactly? Can you ask the builder?

---

My theories:

• After the siding was installed someone noticed that the hole is in the wrong location so a new one was drilled but there is no incentive to fix the old one
• Homeowner changed their mind about dryer location. New hole was made but old hole was finished just in case homeowner changes their mind again

Answer 3

My guess here is that there was a basement bathroom going in and this was going to be the exhaust out for the fan. This would fit the location and size.

You don't have to do anything right now except put a screen over it. Without it being a properly ducted orifice there is a requirement for a screen on basement air vents.

So...

1. Put a screen on it.
2. Cover it... I would use plywood and small screws so that you could reuse it if you want in the future. Then just throw some insulation over the plywood.