Pole barn purlin help!

[QRTRHRS]

I re-tinned a pole building that was built in the mid 70's. From the ground, before we started to tear off the old tin, the purlins (on edge btw) looked aweful. The original tin was nailed on and leaked in around 3500 places (every frackin' nail basically). we figured that the leaking over the years had ruined all the purlins and they did look bad. However, once we got the old tin off and got up there, none of them were bad. We walked on the roof as we tinned it, and none of the purlins had any issue. I was amazed. Now, the wall girts were a different story. They were damaged from machinery running into them and breaking them, and since we were now constructin wainscott on this building, the girts were essentially all in the wrong places, and half of them broken anyway. so all of those were removed and replaced with new. Cheap to do really, on this 32 x 50 building, and made interior much cleaner looking too. Later I reused every single removed 2x4 for another building re-roof.
My re-tinned building did not ever have insulation, so maybe that is why the purlins survived al the years of leaking nails, because they were allowed to dry out between rains. the insulation maybe held the water close to your 2x4s and ruined them. Anyway, in case you havent actually touched them yet, they may look bad from the ground due to water staining, but still be serviceable.
We have been putting a layer of Tyvek housewrap on top of the purlins, under the tin screwed on. It gives us a second barrier in case any leaks develop. If there was a leak, the water would run down to the vented soffit instead of dripping inside the building. This includes condensation, if any ever ocurrs.

Have you put an ad in the papers for help? Maybe if you did you could kind of interview the reponders and choose one to work with/for you.

I like bubble wrap with foil on both sides under the roof tin. Cuts the rain noise alot as well as the condensation. Relatively inexpensive and available in six foot widths.

 

[EddieWalker]

I don't have a lot of experience with this, but have done a few. Unless the trusses are 4 feet apart, you have to have the roof purlins on edge to have any long lasting strength. With a 6ft spacing, you are fine with 2x4 on edge, which is normal and proper. Putting them flat will cause them to sag over time and anybody who suggests that you do so just so it's easier for them to attach the roof is an amateur and incompetent.

Installing the metal screws is very easy when you put the metal up and you can line up the purlins. It's only 3ft, so it's pretty easy to hit the edge of a 2x every time. Even with rolls of bubble insulation up, you can see the purlins through the insulation easily.

Your plan of removing sections of the metal roof and replacing it as you go creates a lot more work and takes more time. The best way to to remove all of it, or at least one half of it, and then addressing the rotten wood and putting on the new metal.

You absolutely HAVE to have good air flow from the eves to the peak on a metal roof to keep the wood dry. Metal roofs create condensation more then any other type of roof. Air movement across the bottom of the metal will dry out the condensation and stop the moisture from rotting the wood. Give yourself some overhang at the eaves and leave the ends open. The shape of an R Panel is perfect for allowing air to flow in, and then install a ridge vent to allow air to exit.

Have you tried Angies List to find somebody to do the work? This is where I go to find somebody when I don't have a good recommendation or already know somebody. I also like to use Facebook when looking for somebody to do something. For me, it's all about getting a list of names, and then seeing if they are who I want to hire. Facebook is good because it allows me to ask a question to a lot of people, just like here. Then I look up that person on FB and see if they have pics of their work. Funny thing is some guys will post pics of what they do, and it's terrible, or not what I'm wanting out of who I plan to hire.

Lastly, trust your inner voice. If you have doubts about the guy you are talking to, don't hire him. In every case where I've been hired to finish off a job, or totally redo what was just done, the clients tell me how they knew he wasn't the right person, but hoped it would get better, or they where wanting it done right away and hoped for the best when hiring him.

Good luck,
Eddie

 

[SPIKER]

I'm surprised no one caught onto the 1 part roofing. The issue is with the LONG sections of roofing is they are very flimsy and will fold up AND bend/kink like crazy. Even 14' are difficult to move about and place without bending them. I also agree with the above post about removing 1/2 of roof or building and then continuing on. The 2x4 on edge is not all that common but does add some additional structural to the roof. I would still keep them closer span, I think they are on 4' is ok, but 6' is a bit far for metal as most of the metal is pretty thin stuff.

Mark

 

[jimgerken]

I'm surprised no one caught onto the 1 part roofing. The issue is with the LONG sections of roofing is they are very flimsy and will fold up AND bend/kink like crazy. Even 14' are difficult to move about and place without bending them. I also agree with the above post about removing 1/2 of roof or building and then continuing on. The 2x4 on edge is not all that common but does add some additional structural to the roof. I would still keep them closer span, I think they are on 4' is ok, but 6' is a bit far for metal as most of the metal is pretty thin stuff.

Mark

I re-read the original post, and I think you mis-understood the specs. The roof purlins are on edge and on 24 inch centers, not 4 or 6 feet.
As to long sheets: I have worked with sheets as long as 41 feet. It is tough to get them delivered and unloaded without damaging the edges, but if you can get the tin supplier to use a couple cover sheets it helps, and get the driver to use more than two straps when unloading it too, it helps. After that it comes down to having enough hands to lift them without kinking. On the 41 footers we had 4 guys. 32footers will need three guys. Another good trick is to build a ramp of sorts, at the point where the roof is closest to the ground, so you can slide the sheets up. Think of it this way: A sawhorse that is about 5 feet tall, then five feet closer to the building a sawhorse that is 8 feet tall, then five feet closer a sawhorse that is 11 feet tall, OK, you get the point. They dont have to be actual sawhorses of course, but now you have the concept. Cover them with carpet if you are really ****. Or you can use some automation. Let me see,,, Yup, here are some pics of a deal I built to handle long steel sheets...

 

[Oliver1655]

I have a 22' boom for my loader. I reach over 4-5 sheets lengthwise & place a couple of slings under the sheets to lift them. I use short cam action straps between the slings & the boom which makes it easy to lower the sheets to the roof. I have another strap with a hook which is placed over the ends of the sheet closest to the tractor to prevent them from sliding out of the slings. The slings bow the sheets side to side & keep them from kinking. This setup works for side walls up to 12' no problems. If it is higher, it will still lift the sheets over the roof part way & allow you to slide them up the rest of the way lice the ramp mentioned earlier. (Note - On some loaders where the lift arm cylinders are pinned to the lift arms there may be several holes. If so, if you use the set of holes closest to the driver, it will allow you the highest reach. If you use the furthest set of holes, you lose reach but gain digging depth.)

The boom has sure made life easier for many things.:thumbsup:

John

 

[Midniteoyl]

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I re-read the original post, and I think you mis-understood the specs. The roof purlins are on edge and on 24 inch centers, not 4 or 6 feet.

Ya.. same as mine.. The trusses are @ 8 feet with 10 foot purlins 2 feet apart, on edge.

 

[Notforhire]

Does using a sheet 40ft long create any problems with expansion? Is there any advantage to using two 20ft sheets instead? I don't mean handling, or installing, just the expansion issue.

Bill

 

[jimgerken]

I don't know what the practical limit on length is, from the perspecive of expansion and contraction due to temperature change. In my case, the 41 footers were a ceiling. The pics I posted showing roofing were 25 footers. I don't know how much the Original Poster's desired 32 footers used as roofing, would expand and contract. From the handling standpoint, I would want to use a single pc for the 32 foot span. It would avoid the overlap, where 4 corners all stack up and it never looks right. My opinion anyway.

 

[EddieWalker]

I don't know what the practical limit on length is, from the perspecive of expansion and contraction due to temperature change. In my case, the 41 footers were a ceiling. The pics I posted showing roofing were 25 footers. I don't know how much the Original Poster's desired 32 footers used as roofing, would expand and contract. From the handling standpoint, I would want to use a single pc for the 32 foot span. It would avoid the overlap, where 4 corners all stack up and it never looks right. My opinion anyway.

I agree with everything and will add that whatever the expansion of the metal is, it's so minimal as to not be a concern as long as quality screws are used.

Eddie