Would you buy a rental with a crawl space?

12 Replies

Hi everyone.  I'm looking at a rental with a crawl space and I've never owned a house with one. From anyone who has or has had rentals with crawls, is there any reason you see not to buy a property with a crawl? 

Note: The numbers look good and I would get an inspection and contractor quote before closing. 

Thanks in advance. 


@Joe Mazur - Most of our rentals have crawl spaces. Its actually much easier with a crawl space to address electrical and plumbing issues vs. slab. Check for termites and any obvious signs of water intrusion, but outside of that I would not be worried. 

I'm the opposite. I've only owned houses with crawl spaces. Like mentioned above, it makes it much easier to address plumbing and electrical. I'm hesitant to buy a house built on a slab. 

Crawl spaces are just like attic spaces but upside down.  Just make sure it has proper ventilation to the crawl space. This is required by the building code.  IBC 2009 (commercial code) defines the requirements in chapter 12.  I don't have the IRC (residential code) handy.  Cross ventilation or on all sides is the best.  The vents or louvers should have insect screens on the side.  Make sure there are no holes so critters can get into this space.  You may want to insulate the floor depending on where the wall insulation is located at.


The only issue I've had with crawlspaces is cross ventilation problems.  If you open the access door and get a musty smell, then there's excess moisture down there and you may need to have it lined with moisture barriers or sump pumped. Not that big of a deal though.  Easy access to area for cables, electrical, plumbing et cetera.

I wouldn't worry.

Hi Account Closed

This is some awesome insight. Thanks a ton guys

sounds like slab < crawlspace < regular basement < finished basement

@Joe Mazur In my area, probably half of all homes are on crawl space.  It's considered as good as any other structure.  Most termite companies can check moisture levels under the house to make sure everything is ok.  It's always a good idea to have a moisture barrier covering the bare ground to prevent moisture transfer between the ground and house.  The International Building Code requires ventilation but there are deeply divided opinions within the building and HVAC industries about whether it's best to ventilate or seal the space.  Inspectors always make me put vents in, then my HVAC guy tells me to close them all up.  It's not a big deal either way but I just wanted to throw that in.  Good luck!

Always provide ventilation to a crawl space. If you don't, you will create a mold problem and the wood structure will start to decay and rot out on you.  Remember this is an attic space just flipped upside down and we always ventilate an attic. Right? 

Geek terms: =) The International Building Code (IBC) and International Energy Conservation Code (IECC) requires them.   Based on IBC 2009 1203.2.1  requires 1sq ft of ventilation per 150sq ft of building footprint.  Now if you have a vapor barrier this can be reduced down to 1 sq ft of ventilation per 1500 sq ft of building area per 1203.3.2 exception 2.  There are some exceptions per code but what is stated is a good rule of thumb to follow.  ASHRAE 90.1 addresses this from a mechanical standpoint as well.

I would look to see if there is R-30 (for Michigan area) of insulation under the floor.  If the insulation is sprayfoam or polystyrene (pink or blue stuff) then you will get a vapor retard to some level.  Vapor retarder goes on the warm side (interior) of the wall, floor or roof, Michigan is heating that cooling (70/30%) throughout the year.  Now if you are in Tennessee its just the opposite, more cooling about a 60/40% split.   Now in Tennessee I would still keep the vapor retarder to the interior side due being north of the "Warm-Humid" zone defined by IECC Climate zone map.  

Now this is in general terms as we know nothing about the construction of the rental property.  Message me if you specific questions on this topic.

First to answer your question, I would and have. I like Max's equation, above. I dislike houses on slabs, and we don't really see that around here anyway. 

Next, there is very good research that shows that the old way of dealing with crawlspaces - open vents and plastic on the floor - is actually a poor way of protecting air quality. The new method is a total dry-in approach wherein the crawl space is completely sealed off from the outside atmosphere. There is a research center here in NC funded by a consortium of trades and government that has data going on hundreds of houses regarding air quality, growth of mold spores, etc., and encapsulation is the key to avoiding most of that stuff. Of course, it really needs to be done from the beginning, as retrofitting is not easy, especially if you have a gas furnace in the crawlspace, poor drainage, etc. 

I love houses with crawlspaces.

I thought putting plastic on the ground in crawl spaces is now not recommended.  At one time twenty years ago, it was all the rage.  Now, I think the general best practice is to ensure the crawl space is dry, adequately ventilated, and pest free.

I think it's an apples to oranges comparison to compare crawlspaces to basements.  To me, it's two discrete comparisons.  

concrete slab < tiny crawlspace < tall crawlwalkspace

unfinished basement < finished basement

In my area, most SFH have at least a crawl space if not more. When I check out potential properties, I have no problem going under the house and checking around tub, sink and toilet drainage lines for wood rot/water leak history. Also, floor reinforcement history in regards to support pillars and/or joist repairs. I think its a must to be able to check under the floor for any surprises that you don't see when you are in the house.

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