crawl space insulation

[Jeff Thies]

I bought a small 60's house in Atlanta for a rental.

I'd like to tighten the thermal envelope and get the best bang for the buck and tackle the weakest links first. There is no underfloor insulation. Cinder block crawl space, handful of small vents. Vapor barrier on ground.

The outside has been done in vinyl with some sheet insulation under and then the old black fiber board under that, probably nothing in the wall. Need to look. Maybe R4 total. Windows are new and OK.

As poor as all that is, it isn't hard to heat. It's only 900 SF, natural gas heater. Flexible, I believe uninsulated or low insulated duct.

I'm thinking of leaving the walls alone for now, blowing in some cellulose later.

My first impression on the floor was to push in some fiberglass. Now, I wonder if I shouldn't insulate the crawlspace walls instead. Rigid foam board shiny side out, perhaps spaced off the wall to add an extra R1, perhaps not.

Thoughts?

Jeff

[Evan]

It sounds more to me like if you really are out to make money with all these rental properties you are buying that you should have at least a plumber, energy auditing firm and home inspector under contract for you to advise you on some of these matters rather than a using a Usenet group for obtaining such advice...

Property management is not a hobby, it is a business...

~~ Evan

[Jeff Thies]

The fabulous thing about usenet is that you can always find someone who just doesn't like you and is more than willing to make that point.

I took care of Mom for a number of years, in every way possible, and it drained whatever I had. I have a small inheritance, and I mean small that I need to do something with. I have friends that have managed properties and have advised on buying real estate and they are helping.

Now, lets say I contracted out a plumber, and an energy auditor and a home inspector, to make all those people and yourself happy. What would I have left? On a 14K house? I assure you that no one else is doing what you suggest in this neighborhood.

As far as investments, there is no better investment now than real estate, if you have cash. Not that this house was ever worth 125K, but some genius had paid that for it at one point. Welcome to reality. Mine, not yours.

I get advice and help wherever I can, not just here. I've dealt with a myriad of problems that I never brought here. And I don't mean easy ones at that. What I have now is a house in as good a shape or better than any on the street (fully furnished and decorated) that I have been offered $700/month, on right at 17K in. You may think that is terrible, I don't. My reality is tougher than yours.

Jeff

[jamesgangnc]

Insulating the crawlspace walls is beoming popular. Here in NC what I have seen has been both the crawlspace walls and the floor. But it will be a lot cheaper to add insulation to just the crawlspace walls. Regular isulation is cheaper and has higher r than the rigid foam board. Are the crawlspace walls convetional 2x4 framing? Most of your heat/cooling losses are in the roof first, the walls second, the floor last.

[Jeff Thies]

Way, less trouble too.

Nope, just cement block. I suppose I could staple it to the sill and let it hang down. Wonder which way to face vapor barrier, probably does not matter much...

Jeff

Most of

[Colbyt]

Where is the furnace and where are the duct runs. Heat rises faster than it is lost to the sides. Most folks like warm floors.

You will need access to all plumbing and wiring under the house at some future time. Fiberglass batts if you feel you must.

Superb attic insulation and caulking all cold air entry points to interior will best your best bang for your and the tenant's buck. That far south You would have to compute the increased savings from more in the attic. The first 6" is always the best bang for your buck.

To those smart asses who are critical, making sure your tenant's utility bills are reasonable helps ensure that they have enough money to pay the rent.

[Jeff Thies]

It's in the crawl.

I think I'll hang some batts on the crawl walls.

Leave the little bit of venting, at least that near the furnace.

I'll pass then.

I wish! There is no attic, only about 10" from roof to ceiling. Tall angled ceilings. I think there may be blown fiberglass up there, found some in the wall. If there isn't, I'm going to blow cellulose in somehow. I'm going to track down the neighborhood chief and see if they have any architectural plans. It's an odd very hilly neighborhood, there are about 4 styles that adapt to the slope of the terrain. Houses were in the teens in the 60's. I rather like it, small and easy to care for and climate condition and the neighborhood would be boring if it were flat! Big houses have more problems and this is a great time to play small bore and not excess consumption.

and caulking all cold air entry points to interior

Weather seal is good.

That far south You

My thoughts exactly! And, low bills are hard to move away from.

Cheers, Jeff

[krw]

50% return? That's not bad at all! It might even be an inflation beater. :-(

[krw]

I'd the floor and try to get some vapor barrier in there, too. If you can actually crawl in your crawlspace it's not all that difficult to put insulation between the joists. Do it in the Winter, though. Colder the better.

The vapor barrier goes towards the heated side. I'm not a fan of fiberglass insulation against block, though. It is tough to know where the moisture is going to come from.

[krw]

I wouldn't do that! You'll more than likely cut off any roof ventilation and you'll be paying for a new roof soon(er).

[Edward Reid]

You are in termite country. Whatever you do, do NOT obscure the view of the crawl space walls. If you cover them, do it with something transparent. The termite inspector needs to be able to see termite tubes. (You can be the termite inspector if you know what to look for and remember to do it regularly. Or you can hire a professional. But you need to make sure it's done.)

That "handful of small vents" is far more an issue than the lack of insulation. (If your windows were leaking around the frame, would you install double glazing before caulking?) But you have to stop moisture getting in before you seal those vents. Chances are that the vapor barrier is useless. Most things call vapor barriers are just sheets of polyethylene thrown down on the ground. To work, it must be TOTALLY sealed, every seam and joint caulked (silicone etc) and joined to each post and all walls with caulking. Seal the crawl space floor properly using 6-mil poly and then you can close those vents. The cinder block won't let enough moisture through to worry about.

The ground in your area isn't all that cold, so with the vents closed, insulation under the floor won't be important. (You've already indicated that the situation isn't all that bad.) If you want actual data to base your decisions on, get a remote-reading thermometer / hygrometer and install the remote in the crawl space. Likely you'll find that the crawl space temperature is closer to the inside temperature than to the outside, and even closer after you seal the vents. Use the hygrometer to assure that your vapor barrier is working, since you don't want the humidity in the crawl space to be consistently above 70%, where moisture damage begins.

Edward

[Robert Green]

That's an excellent point and gets me to thinking that the AHR "brain trust" could probably generate a very useful "inspection" list for each of the four seasons.

I've decided to break down and get one of those fiber optic tube cameras that HF sells to help me inspect areas that just can't be seen easily. With a "stalk cam" and a few strategically placed inspection holes I should be able to much better inspect the house for critter signs. The problem I've run into when evaluating places with "no live termite infestation" (codespeak for "found old infestation") on their certificate is that you can't get behind plywood walls in basements and up in suspended ceilings, two of the places where I've seen the most evidence and unfortunately, the most damage.

I assume from termites liking to stay at ground level that a crawl space is a great way for them to get from the ground to the wood in the structure unless you're very careful. Probably mud tube their way up the footings. My neighbor built a porch on footings, "skirted" the empty space under it with wood in direct contact with the ground and the outcome was predictable. Once your neighbor builds a nice, healthy colony, your house is next. The neighbor on the other side and their neighbor got infested from *their* neighbor who kept an outdoor stack of junk wood in direct contact with the ground. The termites converted all that food mass into more termites which went looking for other food sources. )-:

I've been using bait tubes (plastic tubes filled with cardboard soaked in bait) but it's often hard to tell termite damage from water damage - the cardboard is quite fragile. One thing I've noticed is that cardboard is to termites what peanut butter is to rodents - an irresistible food source. Cardboard was the target of two of the three termite infestations I've seen close up. In one case, they even started eating the Styrofoam around an air conditioner in a plastic bag (hah! as if that stopped them) in a cardboard box in the shed. My neighbor's basement door just fell out of its frame one say. Termites are fascinating because they leave the structure apparently intact, but all eaten up just below the surface. Just like bankers!

I think termites are unique in that they carry all three of the major trunks of the tree of life Eubacteria, Eukaryotes and Archaea within their bodies (and probably virii as well). I think there might be one other bug, the wood eating cockroach that can do this but my memory on this is very hazy . . . In looking that up I also discovered that Aussies call them "white ants." Crikey mates, them ain't ants!

-- Bobby G.