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General => General Forum => Topic started by: bobtheengineer on April 03, 2008, 09:33:07 AM

Title: under floor joist protection
Post by: bobtheengineer on April 03, 2008, 09:33:07 AM
I was just wondering what most people used for covering up the underside of the floor joists?  Something cheap, tough, and keeps the critters out.

Any help is appreciated.

Thanks
Title: Re: under floor joist protection
Post by: ScottA on April 03, 2008, 09:42:01 AM
I'm planning to use primed 7/16 OSB.
Title: Re: under floor joist protection
Post by: MountainDon on April 03, 2008, 09:55:41 AM
OSB, pegboard, plywood, have all been mentioned in previous topics.

Also whether to vent or not. That's why pegboard was mentioned. Using wire hardware cloth with 1/4 inch openings has been mentioned, either partial in conjunction with one of the above, or full coverage.

I have never found a reference to closing the bottom of the joists after insulating in any professional guide or code book. However, if the space is not going to be completely skirted in a rodent proof manner it is, IMO imperative to do something to keep the mice, etc out of the insulation - usually fiberglass. They love to nest in that stuff.

Ideas gratefully accepted.
Title: Re: under floor joist protection
Post by: pioneergal on April 03, 2008, 12:32:43 PM
We insulated and then stapled TYVEK (housewrap) to the underside of the joist. We did that about 18 months ago and so far so good. There does not appear to be any problems but we will check again in a few months to see if we need to do something different.
Title: Re: under floor joist protection
Post by: MountainDon on April 03, 2008, 02:12:40 PM
Might be good. No sunlight under there to cause deterioration I'd suppose.

Watch for any small spots where mice could have chewed a small entry hole. That's what I worry about more than anything else. They don't need much of a hole and they will chew anything.
Title: Re: under floor joist protection
Post by: Redoverfarm on April 03, 2008, 02:48:21 PM
IMO hardware cloth or rabbit wire 1/4" grid is probably the best bet.  Best price I have gotten for galvanized is about $1 foot.  100 ft roll was $109. Have went through 2 rolls for the chink on my logs.
Title: Re: under floor joist protection
Post by: wingam00 on April 03, 2008, 04:48:45 PM
I used under my house  4' x 100' orange Warning Barrier Fencing. A roll cost about $35 and  won't kink, bend or corrode , Easy to handle and use, & UV resistant.  This is the best bang for the buck that I found, cheaper and easier to install than chicken wire. Easy to install with a stapler and scissors. Easy on the back if you are crawling under it  and rub up to with you back. 
Here is a lick to lowes with a picture but many places care it. http://www.lowes.com/lowes/lkn?action=productDetail&productId=137-304-RC104100-6P&lpage=none (http://www.lowes.com/lowes/lkn?action=productDetail&productId=137-304-RC104100-6P&lpage=none)

Mark
Title: Re: under floor joist protection
Post by: Willy on April 03, 2008, 04:58:48 PM
I will be enclosing the craw space sides with hardy board for fire reasons. It keeps embers from blowing under and won't burn if a low grass fire goes thru. I will put part of the board under ground and attach the rest to the beams right up to the sideing level. Thinking of making a access to the craw space from inside my closet by the front door. I get under my home thru a door under the stairs and it is nice not digging out snow and crawing in the hard way. Mark
Title: Re: under floor joist protection
Post by: Redoverfarm on April 03, 2008, 05:14:11 PM
wingam00 that fine and dandy if you are worried about someone driving under there.  ;D  No seriously the reason for the rabbit wire is the critters. As Don stated that most of the cabins are built in the woods or woods closeby. This will be a open attraction for field mice or wood mice when temperature starts to fall in the fall or early winter.  Once they embed themselves in the insulation it is hard to eradicate them.  Not sure how effective it is as I have heard that a mouse can enter via 1/4" hole and rats 1/2" hole. The wire is strong enough that they will not chew through it like screen.
Title: Re: under floor joist protection
Post by: MountainDon on April 03, 2008, 06:51:57 PM
Yep. Mice are smaller than they appear to be. They can squish themselves down and enter through a 1/4 inch space such as a space under a door, or a small hole they gnaw and enlarge just enough to get through. A 1/4 inch diameter hole is not sufficient to allow direct entrance, but they can gnaw it large enough. We've been down the rodent exclusion road a number of times before.

The plastic netting will keep the larger rodents out UNLESS they want to see what they're being kept from. Then they will chew through. Chicken wire would be a better deterrent for larger rodents, but a determined rat for example can eventually get through even that.

The NPS Rodent Exclusion Manual is here (http://countryplans.com/smf/index.php?topic=2919.0)

Other threads with references to mice problems
http://countryplans.com/smf/index.php?topic=4177.msg50180#msg50180
http://countryplans.com/smf/index.php?topic=3268.msg36353#msg36353
http://countryplans.com/smf/index.php?topic=3179.msg34475#msg34475
http://countryplans.com/smf/index.php?topic=2916.msg30530#msg30530
Title: Re: under floor joist protection
Post by: glenn kangiser on April 03, 2008, 10:46:57 PM
I thought we thought that 1/4 x 1/4 hardware cloth would keep mice out -- yup -- I failed to read all of the posts. [crz]
Title: Re: under floor joist protection
Post by: ScottA on April 04, 2008, 07:08:13 PM
I'd like to mention that squirrels can chew through sheet metal if they find a loose edge. Don't ask me how I know this.  d*
Title: Re: under floor joist protection
Post by: gandalfthegrey on April 04, 2008, 07:19:25 PM
I don't do metal   only coffee........OOPs! d* c*
Title: Re: under floor joist protection
Post by: MountainDon on April 04, 2008, 07:53:05 PM
Quote from: ScottA on April 04, 2008, 07:08:13 PM
I'd like to mention that squirrels can chew through sheet metal if they find a loose edge. Don't ask me how I know this.  d*
Yes a determined rodent might, but wood should be easier for them.
Title: Re: under floor joist protection
Post by: gandalfthegrey on April 04, 2008, 08:30:34 PM
Actually i remember Squirrles in our house in PA. Through the attic vent.  My father had piut mesh over the opening but they got in somehow....I do believe they got through the mesh...
Title: Re: under floor joist protection
Post by: rakuz66 on April 05, 2008, 07:14:04 AM
I'm at this stage myself.  I'm thinking of not insulating underneath and just skirting.  If, ther's no insulation, will the mice come???
Title: Re: under floor joist protection
Post by: Redoverfarm on April 05, 2008, 07:20:16 AM
Most likely they will come whether it is insulated or not.  They will seek some warmth from the winter in a sheltered place.  Then add the combination of some hint of food nearby and that usually is the icing on the cake. But changes are if there is no access when warm temperatures rise the guest will leave.
Title: Re: under floor joist protection
Post by: glenn kangiser on April 05, 2008, 08:40:32 AM
Well said, John.

We don't have a problem here, but only because we do as every supermarket amd fine feeding establishment does.  Plenty of De-con bait stations around besides keeping the things they like away.  I can't put screen under my crawlspace.  I live in it.  [crz]