Cheap 2-pin wood moisture meter

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I'm looking at the following at Harbor Freight:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber'57
It's $20, and I wonder if it's worth the money. My initial purpose for it is to find leaks in my attic. I just had total roof job done to my very old house and there's a lot of discolored wood up there and have to guess if wood is wet or not. I figure the meter might make finding leaks a lot easier than digging my finger nail into a piece of wood or rubbing it with my hand.
Also, it might come in handy when trying to determine if wood is moist or not. For instance, is it ready to prime/paint yet? Might it warp or check unless allowed to dry further? Maybe picking out lumber at Home Depot, etc.
Thanks for any information.
Dan
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Will that tell you what you need to know? What if the wood has rotted, but is dry?
Dan_Musicant wrote:

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wrote:
:Will that tell you what you need to know? What if the wood has :rotted, but is dry?
I suppose it wouldn't help with wood that's dryrotten but not wet. I want to be able to go into my fairly dark attic and find wet wood, if any. I see stained wood but it's generally from past leaks, not present ones. The house is 95 years old and there were a lot of leaks in the attic but it appears that they were just about all fixed before they caused dryrot. However, I want to make sure that my recent roof job was adequate, and will be checking for leaks. A wood moisture meter might really help with that. : :Dan_Musicant wrote: : :> It's $20, and I wonder if it's worth the money. My initial purpose for :> it is to find leaks in my attic. I just had total roof job done to my :> very old house and there's a lot of discolored wood up there and have to :> guess if wood is wet or not. I figure the meter might make finding leaks :> a lot easier than digging my finger nail into a piece of wood or rubbing :> it with my hand.
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The info you get from a moisture meter isn't well suited for detecting roof leaks. Oh, it'll tell you where it's wet, but the moisture you're trying to measure is beyond the meter's real working limits. You'd do as well or better to just feel or eyeball something like a roof leak. It'll be obvious. But they're great for their intended use, at a "proper" lumberyard. HD's wood is for slap-dash, who-cares projects, IMO. Tom
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If you have cedar shingles it is normal for the edges to be damp after a rain. Normal to see day light on a dry day.
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wrote:
:
: :> I'm looking at the following at Harbor Freight: :> :> http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber'57 :> :> It's $20, and I wonder if it's worth the money. My initial purpose for :> it is to find leaks in my attic. I just had total roof job done to my :> very old house and there's a lot of discolored wood up there and have to :> guess if wood is wet or not. I figure the meter might make finding leaks :> a lot easier than digging my finger nail into a piece of wood or rubbing :> it with my hand. : : :If you have cedar shingles it is normal for the edges to be damp after a :rain. Normal to see day light on a dry day. : The bottom-most layer of what they tore off on Oct. 28 and 29 was cedar shingles. Now, what I see from the attick above the skip sheathing is 1/2" CDX plywood, above which is 30# paper and then architectural asphalt composition shingles.
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Well it sounds like they did the job correctly in that respect. I would not worry about it myself. If you see stains now it is most likely from the cedar shingle roof. Cedar shingles swell and seal up the tiny holes when they get wet. Not unusual for there to be a slight bit of seepage until they did.
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wrote:
:
: :> : :> The bottom-most layer of what they tore off on Oct. 28 and 29 was cedar :> shingles. Now, what I see from the attick above the skip sheathing is :> 1/2" CDX plywood, above which is 30# paper and then architectural :> asphalt composition shingles. : :Well it sounds like they did the job correctly in that respect. I would not :worry about it myself. If you see stains now it is most likely from the :cedar shingle roof. Cedar shingles swell and seal up the tiny holes when :they get wet. Not unusual for there to be a slight bit of seepage until :they did. : I see a LOT of signs of seepage, all over the attic, but haven't spotted any dry rot, so it doesn't worry me. What has bothered me is that I can't tell if those signs are current wet spots or spots that dried up decades ago. That's why I want to get this meter. A post I saw in a newsgroup suggested that you can make your own meter just using a multimeter (ohmmeter). I was playing around with a couple of mine last night and found that at the highest ranges they do show readings for wet wood. Thing is, I don't know how to interpret them. I guess I'll just buy the $20 meter.
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Sounds normal to me and I think the job would look shoddy if that many places were leaking now with that type roof.
First, does the decking look normal. It would have to get wet for the wood below it got wet and it would show signs of getting wet not just the wood below it. Second, if you see no signs of wet ceilings or insulation, take a look up there during and or immediately after a rain. If there is a leak it will be wet up there. Third, cedar shingle roofs experienced this every time it rained. No problem so far, right? Nothing falling apart, only dry stains? Fourth, if you have a next door neighbor, ask to take a look inside his attic. His roof was probably originally cedar shake also and probably the inside of his attic looks like yours.
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For 20 bucks,you can't go and buy one and see for yourself????
Even if it doesn't suit you,you can sell it on Ebay,and probably get more for it than your 20 bucks investment.
--
Jim Yanik
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: : :> I'm looking at the following at Harbor Freight: :> :> http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber'57 :> :> It's $20, and I wonder if it's worth the money. My initial purpose for :> it is to find leaks in my attic. I just had total roof job done to my :> very old house and there's a lot of discolored wood up there and have to :> guess if wood is wet or not. I figure the meter might make finding leaks :> a lot easier than digging my finger nail into a piece of wood or rubbing :> it with my hand. :> :> Also, it might come in handy when trying to determine if wood is moist :> or not. For instance, is it ready to prime/paint yet? Might it warp or :> check unless allowed to dry further? Maybe picking out lumber at Home :> Depot, etc. :> :> Thanks for any information. :> :> Dan : : :For 20 bucks,you can't go and buy one and see for yourself???? : :Even if it doesn't suit you,you can sell it on Ebay,and probably get more :for it than your 20 bucks investment.
Yeah, there's a point to that. I figure even if what it tells me isn't accurate, I can make an educated guess what the situation is. It undoubtedly works by measuring the conductivity between the electrodes - basically, it's an ohmmeter.
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There's only two types of moisture meters;the ohmic type,and the RF- absorbtion type. The latter works on the "grid-dip" principle,that an oscillator's output drops under a nearby load capacitively or inductively coupled. IOW,if something that absorbs RF nears the oscillator's antenna,it causes the output to drop depending on how much the load absorbs RF.The meter section measures the RF output,is calibrated to show % of moisture.
dry wood absorbs less RF than wet wood.
--
Jim Yanik
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maybe use a $10 water alarm on a water collecting tarp in the attic test area. move around a day after rain stops to next test spot. see also insulation: http://www.eere.energy.gov/consumer/tips/insulation.html 57 pdf pages about your house at: http://www.eere.energy.gov/consumer/tips/insulation.html
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DAGS on the wreck, this has been asked and answered already. Short version: the HF version doesn't work.
H
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:DAGS on the wreck, this has been asked and answered already. Short :version: the HF version doesn't work. : :H Link?
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:DAGS on the wreck, this has been asked and answered already. Short :version: the HF version doesn't work. : :H DAGS means what?
I see where you said you didn't care for the Harbor Freight one and sent it back and had decided to get a better one:
Back in 2003:
http://groups.google.com/group/rec.woodworking/browse_frm/thread/87da0f2d32ec1903 /
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Yes that's the one. Isn't it a pretty direct answer to your question?
Or, to get to the point, did you DAGS first or post the question first?
I hate to be net nanny, but it seems that's what's happened.
With self-loathing, H
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:Yes that's the one. Isn't it a pretty direct answer to your question? : :Or, to get to the point, did you DAGS first or post the question first? : :I hate to be net nanny, but it seems that's what's happened. : :With self-loathing, :H
Oh, no problem. Now I see what you meant by DAGS. Yes, I did DAGS first (Do a Google search). However, I didn't do it in such a way as to bring that thread to me attention, my bad, I guess. IOW, I could have done it more thoroughly. Anyway, I don't think I've done a ton of harm here.
Could you comment on why you were dissatisfied with the HF meter? You didn't in the thread. Thanks.
Dan
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No, it's I who must apologize for net nannying. I think everyone who's been watching a NG for over 5 years or so begins to be annoyed by the greater percentage of posts. Growing old and getting cranky I guess...
But to answer your question more specifically: when I first bought the HF unit it seemed poorly constructed. Seemed more like a cheap plastic toy. Performance was equivalent. It had several "levels" of measurement, but they didn't measure accurately or even consistently. I suppose it would be OK as long as you don't mind a error margin of +/- 40% moisture content.
Returned it and got some clamps.
Now happy, H
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hylourgos wrote:

I'd say, for Dan's application, the lack of accurate measurement wouldn't be that big a problem if it was consistent -- he doesn't really know what the moisture numbers in the attic should be, and is mostly looking for a spot that's different from all the rest. But the lack of consistency sounds like it's definitely a problem.
I suspect that there's also the problem, even if you did buy it for something like Dan's attic, that in the future there's this temptation to use it for something else and actually believe the numbers it puts out.
Meanwhile, what I'd suggest to Dan as a practical solution is finding some sort of paper that changes color if it gets damp (I'm not sure exactly what to suggest, but some marks with a water-based pen on blotter paper ought to do fine for a start), and thumbtack bits of it up all over the attic in likely spots, and then after a few rainy weeks go up and look at them again and see if any got wet.
- Brooks
--
The "bmoses-nospam" address is valid; no unmunging needed.

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