Odd moisture

[peg_688]

 New addition interior is  rough plumbed , not yet wired . The Hardi was installed two days ago , the decision to add lights is why we cut in the two light blocks .

 

 

 
 Note the sweat / water that is behind the Hardi, it has been very hot here , 85° plus , 1/2" CDX is behind the Hardi , the typar , then the siding . The doors and windows have been open there is a lot of venting going on it has not rained in 10 plus days , the sheathing was dry , (I did not moisture meter it,  I will tomorrow from the inside )

  So is this a dew point , cool Hardi warm inside the addition ? Or is it moisture the heat is pushing out the back of the Hardi?

 How dry is Hardi when they make it ?  I would think it would be cooked to dry it , why would it become wet agian ? The back is not primed so it could pick up a bit of moisture but this much ?

One other light block was cut in on  another wall out of the sun , the south wall , no moisture was seen.

 Wierder yet is how could the MAD , of" Made in USA"   fall  in right behind both cut outs ? Figure the odds if a guy was trying to have that happen  

 Thoughts , Ideas welcomed.
 
 Ah the life of a builder  

[jraabe]

Hummmm.... Just thinking out loud.

The interior is uninsulated so it is pretty cool in the morning with the Typar maybe down to dew point? Could this be just construction moisture soaked up by the siding? Moisture that is driven off on the south side?

A moisture meter might give you clues. Can you measure the back of the siding on the two sides?

[glenn-k]

I have seen this with wet boards.  I put a clear plastic on my shop wall and put clapboard on the back in about May - The sun dried the outside but moisture came out the back and stayed on the plastic where the boards contacted the plastic and beaded up as you see in your pictures.  I would say warm moisture being driven back to the cooler vapor barrier then condensing as it cools - cooler air cannot hold as much moisture so it condenses and runs down between the hot siding and the cooler barrier.  It took months for the siding to dry out- Hardy shouldn't hold as much moisture.  If you back prime it you may have a paint problem as the moisture will want out somewhere.  Concrete products that are not sealed can pass moisture - probably includes cement board.

[peg_688]

I can check the uninstalled siding , but can't get to the back of the installed stuff.

 Not sure my moisture meter probes will go in or if it has a cement setting . I have used it on liht weight concrete before it read about the same as the surrounding wood , not sure if that was a "True" reading.  

 MTL it is just ground moisture/ Hardi being stored close to the gnd , mabe not fully cured?? It is not stamped so I have no idea when it was made ,  and the combination of this hot weather. Never have seen this before and it's not uncommon to have to cut in a block . Mostly that was with wood siding not Hardi. Might just be another reason for me not to like it  

 Something else to go wrong   As if theres not enought other stuff  

[jonseyhay]

Pegg,
Do you know if that is Hardie linea weaterboard? Looks like the same as the stuff I have used. Mine has a beveled back same as timber weatherboard and is about 16mm (bit over1/2") thick. I don't have a moisture problem here because we are so dry.

[peg_688]

All the Hardi I've seen here is about 5/16 thick about  about .79 CM I think ?

And it's all flat, no bevel . Some is wood grained , looks like fake wood grain , wonder why ? Well cuz it is   Cement don't have no grain  

 This batch is smooth faced , a bit rough on the back as normal, it's suppose to be 6" wide but it varies up to 6 1/4" in width . Which also is a PITB as we snap top lines , Hardi is suppose to be all alike, it's man made it should not vary at all , well no more then a 1/64 th or so.

   One of the sell points is the top snapping /setting /speed . Well if the top / width is not not consistant  and you need to snap botton lines that sell point is moot . Or worsta lie / false advertizing  

 Just like Trex suppose to be constistant , it ain't either , varies in width and thickness different batchs vary.

  Don't mix 16' with 20' pieces , or you'll have little misalinements, " toe catchers"

   End of mini rant    

 Where as dry as we get right now , no rain in 11 days , none for 6 more they say.

Ground is pretty dry , grass is dieing / drying out a bit early this year.
 

[jonseyhay]

Different stuff Pegg, the product we have here is a lot better than that for consistency in size.  It has no grain just smooth and is joined board to board with a tongue and grove system. We are having a few showers today but no real rain we haven't had any of that since last winter.

[peg_688]

Jonsey could you posta few picies of your down under true Hardi?   I'd
like to compare what being sold here in the US to the org product.

 MTL we're being sold a bill of goods from your decription of your product.

 All the Hardi I've seen is a bout 5/16" thick, and flat .  The proper instalation calls for a 3/16" gap between butt joints / corners / window etc. The joint is then caulked witha latex acrylic caulk , the whole works paint within 90 days , IIRC on the painting part.

 We used some sheet Hardi on the tall narrow , read ugly,  house we did , it was also 5/16"ish thick . No grain , And some 5/4" trim around the window / doors and for corner brds . That was full 1" thick sort of smoothish althought not a s smooth as the Hardi siding. It was a $%#^& to nail , the edges where quite rough etc . Looked/ looks like shidbl hockey sticks to me  

 All the Hardi I've used is ten feet long , except the sheet goods they where 4'x 8' .

 But hey I'm just the guy who builds it . What ever ! As Paris Hilton would say  

 Thanks glad your getting some rain , I hear you all need it.

 PEG

[jonseyhay]

Pegg here is a link to the Hardies web site. If you go to the tech files section for each product you will find information on fixing, waterproofing and such. Hardies product where mostly made in Australia but they have recently move offshore I think to the Netherlands because of all the problems with compensation payments for asbestos victims over here. Their products are widely used in New Zealand and Australia and overall I think they are pretty good.  The stuff I am using is called Linea weatherboad and is very different from the board you are using which I think is probably HardiPlank Cladding. I think Hardies have just move into the US market and although some of their products have been available, you will probably see more coming on stream soon. The web site is worth bookmarking as it has a lot of useful tech help on it.

http://www.jameshardie.com.au/Products/Weatherboards/

[JRR]

I wonder if this isn't happening ...

Everything cools down during the night since the ventilation is "open".  During the morning hours, wet warm air rises from the ground along the wall.  The Hardie begins to warm also, ... but the membrane (being white and coupled with the cooler CDX) provides an opportunity for condensation.

If you spray painted the membrane all black, the situation might change... at least, in the cut-out.

[peg_688]

The Hardi is 16 % MC the plywood 6% , at least by our moisture meter. MTL it is just a wierd situation where the Hardi has some moisture the hot sun is pushing the moisture out the back . Once the walls are insulated the dew point situation should go away and the Hardi will dry out some now that it's off the ground.

 Light blocks are all installed so time will tell.

Thanks , PEG

[jonseyhay]

Pegg,
Here are a few shots of the linea on my job. It is a fiber cement product and as such, it is not as easy to work as timber. The cutting, being the main problem (it's dusty and you need the right saw blades for it). Once on the wall and painted you wouldn't know it wasn't timber unless you look real close. One of the good things about it is, it is low maintenance, no rot problems and it is quite stable (doesn't move round much)  

     

This is a shot of the cut end. It's 16mm thick and you can see the slight bevel near the top. The lap on the boards is around 30mm give or take. (I used a story rod to give me even boards, finishing with a full board under the eaves)

     

Another shot showing the tongue and grove joint. The boards are nailed the same as timber. They are joined offstud so you don't get a hump at the join (we don't normally use sheathing like you)

     

This is a shot of the window trim with the scriber in place.

[peg_688]

Thanks Jonsey.  No sheathing , where do you get your shear strength? Let in bracing ? Metal diagonals ??

 So the  T&G acts like a butt block/  stiffener at the joint . As thick as your Hardi is I'm sure it plenty strong at that joint .  Do they want you to caulk the joint before the two are engaged?  That would seem to be the best weather proofing  for the joint.   Ten foot lenghts ??

It must weight a ton per piece

 So your harvest must be winding down your spending a bit more time here.

 Hope all is well and your harvest went well  

PEG    

[jonseyhay]

Yes, let in bracing is how we do that. I used steel angle on my place but it can be strapping or let in timber. There is, in the code a certain number of bracing units on the structure required for each wind area. They have to be shown on the plan when submitted. The sheathing inside and out (drywall/weatherboard) can be used as a bracing unit as well, depending on the fixing /nailing pattern. I have also used rafter to bearer strapping on my place although it isn't a requirement for this wind area.
That stuff is heavy especially if you are trying to handle it by yourself. The boards are 4.2 meters long. I made up a hanger for one end of the board that nailed to the stud so I could manage it alone.
Yes there is a sealer applied to the back of the t&g joint

[jonseyhay]

We have mostly finished with the cotton and I am now doing a bit of pump maintenance to get them ready for the rice in October. I have a bit more time to work on the house now which is good.

One of the reasons we don't use ply bracing like you is the cost. A sheet of 1/4" construction grade ply runs at around $45 a sheet 1/2" $85. It is sometimes used as a corner bracing on brick veneer buildings though.

[peg_688]

    The boards are 4.2 meters long.

  I made up a hanger for one end of the board that nailed to the stud so I could manage it alone.

 That's 13' 9 3/8"   That must be realllllly heavy.

 They sell a holder deal for the stuff we put up , never used one . We manage ok without it .

 If it was as thick and long as your stuff is we'd be using a silent helper as well,  I'm sure.

 Thanks