Replies

1. 
   DDay | Jan 11, 2008 11:11pm | #1

   I gap and caulk. Anything else will stick out and look poor. From a distance you would still see the seems, similar to vinyl.

1. 
   todd | Jan 11, 2008 11:19pm | #2

   Thanks, wondering that, too.Todd

2. 
   RobWes | Jan 12, 2008 12:57am | #3

   For the life of me I have no idea why they want that gap.

   I used preprimed. My carpenter saw cut every thing and butted tight with #30 splines behind the joints. It does not move and does not look like ####.

3. 
   Jim_Allen | Jan 12, 2008 01:36am | #4

   When I first started using Hardi, I asked the superintendent how he wanted them because he's the boss of the sub. He wanted them caulked. We gapped them slightly and he caulkded.

   The bigger boss came around and said it looks like h e ll and then we butted tight. It does look better.

   Bob's next test date: 12/10/07

4. 
   Notchman | Jan 12, 2008 02:00am | #5

   I've done it both ways, and either way, a bit of caulk is needed just to clean up the butt joint.

   MORE important, IMO, is to flash behind each butt joint with either felt paper strips, metal or plasic flashing strips.

   Whether butted tight or not, water can, and will, get in behind the planks and start its work....the flashing prevents the problem because, over time, at least some of the caulked joints will fail.

5. 
   Scott | Jan 12, 2008 02:15am | #6

   What Notchman said.

   I believe the gaps are for thermal expansion.

   Scott.

   Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”

1. 
   todd | Jan 12, 2008 05:11am | #7

   eenine, meenie, miny, moe...Thanks for the input,
   Todd

1. 
   G80104 | Jan 12, 2008 05:19am | #8

   Vote # 3 as to what the Notchman says!

6. 
   bobbys | Jan 12, 2008 06:21am | #9

   I wish i had taken a picture today to show you, My friend is a carpenter and they were doing a very big wall and the boss said to butt it up tight, This was last year and he asked me, I said it needs a gap even though thats not normal for carpenters to do. Now the whole wall is bulging in different spots, DO NOT BUTT TIGHT, But im in Oregon in rain country so maybe it makes more of a difference here.

1. 
   John @ SoloSider | Jan 12, 2008 06:30am | #10

   Hi Bobbys

   Just wondering how long the wall was and did they leave any expansion room at the trim .

                                         Thanks Cathy (Gold Beach OR.)

1. 
   bobbys | Jan 12, 2008 06:45am | #11

   i think the wall is around 100 feet long. not sure about the ends but i was gonna take a closer look with pictures for my files last week, It looks terrible, I just happen to know my friend butted up tight on it. I did some with the gap and gap at the edges and had no trouble. On another note went yesterday to fix a roof and noticed the siding was stabled on and some was off. This house is around 8 years old, im thinking they blew through with the staples, i did not even know if they could use staples.

1. 
   Jim_Allen | Jan 12, 2008 05:09pm | #14

   Staples is not an approved method of installation. Bob's next test date: 12/10/07

2. 
   Jim_Allen | Jan 12, 2008 05:08pm | #13

   Your real world experiences are welcome.Could you tell more about the conditions? Was it winter or summer? Was it Hardi 8" siding? Does the siding come dry, then get wet and swell after it's installed? Does the siding get sealed (painted) promptly when installed? Bob's next test date: 12/10/07

7. 
   deafbob | Jan 12, 2008 03:24pm | #12

   i think its important to leave a gap and use a good caulk like quad. tight butt joints do show and if caulked, will fail. the caulk needs to be at least  1/8". Bigger is better to a degree with caulk. Give caulk a chance to do its job. I don't know how many times i've seen brand new paint jobs where the caulk fails after months because it was nothing more than a skim coat over a crack. either tight gap with flashing or larger gap with caulk. hardie warranty might be an issue check specs

1. 
   Jim_Allen | Jan 12, 2008 05:13pm | #15

   You are correct Deafbob. Caulk is useless in conditions that move if the bead doesn't have enough thickness to stretch. I don't think 1/8" is enough for most "strectchy" type caulks. Bob's next test date: 12/10/07

1. 
   todd | Jan 12, 2008 09:04pm | #16

   Okay, I am gapping and caulking with Big Stretch. Thanks, all, you're a great resource.Todd