Cost of construction.

[dave1949]

They can decide which works for them and do their own research. If they want to use 2x4's on edge for 8ft spans, that's their choice. I'll never do it, but if it works for you, that's good to hear.
Eddie

Don't you know what the siding is for Eddie? It's there to keep the sag out of those 2x4's.

Seriously, I wouldn't do it either. I'm sure somebody has figured out it is the economic optimum - which means not too many buildings will fail, at least from the building companies perspective and cost of failures.
Dave.

 

[Dano5509]

Does anyone have pricing information when the builder attaches plywood to the roof and walls before putting down the metal roof and siding?

 

[EddieWalker]

There are different types of metal panels. The big savings and advantage of R panels is that they are waterproof just as they are, and the don't require any underlayment or sheething. This allows you to spread your trusses out farther and use purlins to attach your metal. Depending on manufactuer, and metal thickness, you can have purlins from 4 feet to six feet apart. Maybe more, but I"m not sure on that. I like four feet.

If you put plywood on the roof, then you will have to either put your purlins allot closer together, or put in more trusses. I've only seen it done with more trusses.

With a wood undrlayment, you will trap moisture under the metal, so you have to put a water proof membrane under the metal panels. Tar paper works for this, and it's the only material I've seen used.

How thick of plywood and how big the trusses are will affect how much more money this will cost. With the price of metal, it might be cheaper to put shingles on instead of metal if you go to the expense of installing sheething on the roof. If you don't have to buy as many trusses, don't have to buy sheething and paper, then metal is more affordable.

I mostly see this done on commercial jobs and with hidden fastener type of metal panels. I forget the name of those panels right now. Maybe U panels. Anyway, they are not as wide, and don't have the strength to them that R panels do. The hidden fasteners also need to be attached differently then on R panels, which all leads to the need for the wood sheething underneath.

Eddie

 

[smfcpacfp]

I recently had a 30 by 48 X 13 metal pole building built by Cleary Builders. It is built to withstand a 90 per square foot snow load. It has 2 foot overhangs all the way around. 9 by 12 roll up door and a 11' 4" by 12 slide by door and a man door and posts for partitions for a shop area along with two 4 by 5 windows in that area. Cost was just under $22,000 excluding concrete. Here are some pictures of it.

(Pole building construction pictures).

 

[Big Bri]

There are different types of metal panels. The big savings and advantage of R panels is that they are waterproof just as they are, and the don't require any underlayment or sheething. This allows you to spread your trusses out farther and use purlins to attach your metal. Depending on manufactuer, and metal thickness, you can have purlins from 4 feet to six feet apart. Maybe more, but I"m not sure on that. I like four feet.

If you put plywood on the roof, then you will have to either put your purlins allot closer together, or put in more trusses. I've only seen it done with more trusses.

With a wood undrlayment, you will trap moisture under the metal, so you have to put a water proof membrane under the metal panels. Tar paper works for this, and it's the only material I've seen used.

How thick of plywood and how big the trusses are will affect how much more money this will cost. With the price of metal, it might be cheaper to put shingles on instead of metal if you go to the expense of installing sheething on the roof. If you don't have to buy as many trusses, don't have to buy sheething and paper, then metal is more affordable.

I mostly see this done on commercial jobs and with hidden fastener type of metal panels. I forget the name of those panels right now. Maybe U panels. Anyway, they are not as wide, and don't have the strength to them that R panels do. The hidden fasteners also need to be attached differently then on R panels, which all leads to the need for the wood sheething underneath.

Eddie

i built my shed this way but only for the noise factor. . . rain coming down on a "tin" roof sure is loud. by putting the plywood down cut the noise down alot.

 

[ovrszd]

One more point I was thinking about last night.

I remember when I bought and built my first shop. It was a 30x50x10 pole barn. I shopped around and bought the best package I could find. It included all the nails, screws, trim, doors, etc. I can't remember the exact price but it was somewhere around $6K. I was so proud at how cheaply I had bought a building.

I then constructed it, stepped back to admire my new shop, and the stark reality hit me!!!! All I had was a "pop can" building. No floor, no electricity, no lights, no insulation, no water, nothing but a shelter...... Bummer......

So for the next two years I saved money and piece at a time bought everthing I needed to have a shop.

When you get a building quote from a supplier or contractor he is not pricing you a turnkey shop unless you specify it that way. What he's pricing you is a pile of roughin materials plus possibly the labor to nail it together. When he collects his money and leaves you too will realize you just have a basic structure.

The point here is that when you read posts from guys stating what appears to be an awesome bargain price on a building, realize they are probably talking about that pile of materials laying in their driveway or at most a "pop can" shelter standing in their backyard. Nothing even closely resembling a shop.

Of my current $42K shop, the initial investment to get that pile of materials was $19K. The rest is the money it cost to make that pile of materials a useable shop. If you plan to have a year around, work in a T-shirt, well lit, concrete floored, properly wired, modern shop, I think it would be safe to double the price you receive from the supplier of that special package deal.

Edit: Oooppss, wanted to make one more point. In my country pouring bags of sacrete in a post hole is a total waste of time. What's needed in the hole is something that helps the post carry the load without sinking in the hole. First clean the hole down to solid good ole Missouri clay, then put a landscape stone or half a solid concrete block or whatever you can purchase in the bottom of the hole to increase the size of the bottom end of the post that is going to forever hold up your structure. Dry sacrete poured in the hole around the post does not do that in my world. Might be different depending on location/soil type.

 

[wedge40]

Ovrszd. Read post #23. It lays out my plans. Since I'm wanting to put this up without a loan or dipping into retirement, I've been saving to get things going. There will be more incentive to save once I have the shell done.

Someone did bring up a good point in that I want 24" overhang all around. If I want to add a lean-to on after the fact will that be difficult or just put in with the original building?

Wedge

 

[buckeyefarmer]

The trade off on roofing methods is truss rating vs capacity and number of trusses which also dictates purlin sizes which all comes down to cost. Some builders put trusses 8' OC and use purlins on edge between them, either 2x4's on top of the truss or 2x6's hung between the trusses. To span 8' you will have a heavier rated truss, and a physically heavier weighted truss, but you need less of them. Some builders put trusses 4' OC and normally use flat laying purlins on top of the trusses. You need almost twice the number of trusses, but they are each rated less capacity than the 8' OC trusses are, and the weigh less, easier to install. If you want to put decking under the roofing, it will increase the truss specs, more weight per sf dead load to carry, and then you normally have the trusses 2' OC, again more trusses, but each one a little lighter on it's spec. Properly engineered all methods work. Each builder determines which method is more profitable for them to build. I know a lot are now going to the 8' OC (or 9- 12')' and placing the truss in a saddle in the laminated column. This results in smaller header (not really a header since all the truss weight is on the columns).
When comparing prices it's important pay attention to the Live load and dead load rating of the truss. A quotes may assume 0 bottom cord DL, which means you can't later put a ceiling or insulation in your barn. Also, most truss will be 0 bottom cord LL, which means no storage in the truss, don't hang things in the barn from the truss. truss spec should read TCLL (snow & wind loads)-TCDL(roofing weight)-BCLL(usually 0 and not given)-BCDL(ceiling / insulation weight).

The 2x4 or 2x6 on the walls are called girts. The spacing of the purlins and girts can depend on the guage of the roofing and siding and the lumber size used. With 29g, you probably want to stick with 24" OC, but could go more with 2x6's.

 

[ovrszd]

Ovrszd. Read post #23. It lays out my plans. Since I'm wanting to put this up without a loan or dipping into retirement, I've been saving to get things going. There will be more incentive to save once I have the shell done.

Someone did bring up a good point in that I want 24" overhang all around. If I want to add a lean-to on after the fact will that be difficult or just put in with the original building?

Wedge

Yep, I read that post and I understand your plans. Great plans. My lengthy rant was pointed at anyone reading this thread and thinking $7K will buy them a shop. That's not true. There's a lot more to it than a pile of materials.

I had a 20" overhang on my first shop to match my house design. I was planning an addition to it when I lost it. In the planning stages I didn't consider the overhang to be a problem when adding on to the eave side of the building. With that said, and money availability considered, it is always easier to build the whole thing at once rather than add on later. It might also be cheaper. Maybe Eddie can address that??

 

[ovrszd]

The trade off on roofing methods is truss rating vs capacity and number of trusses which also dictates purlin sizes which all comes down to cost. Some builders put trusses 8' OC and use purlins on edge between them, either 2x4's on top of the truss or 2x6's hung between the trusses. To span 8' you will have a heavier rated truss, and a physically heavier weighted truss, but you need less of them. Some builders put trusses 4' OC and normally use flat laying purlins on top of the trusses. You need almost twice the number of trusses, but they are each rated less capacity than the 8' OC trusses are, and the weigh less, easier to install. If you want to put decking under the roofing, it will increase the truss specs, more weight per sf dead load to carry, and then you normally have the trusses 2' OC, again more trusses, but each one a little lighter on it's spec. Properly engineered all methods work. Each builder determines which method is more profitable for them to build. I know a lot are now going to the 8' OC (or 9- 12')' and placing the truss in a saddle in the laminated column. This results in smaller header (not really a header since all the truss weight is on the columns).
When comparing prices it's important pay attention to the Live load and dead load rating of the truss. A quotes may assume 0 bottom cord DL, which means you can't later put a ceiling or insulation in your barn. Also, most truss will be 0 bottom cord LL, which means no storage in the truss, don't hang things in the barn from the truss. truss spec should read TCLL (snow & wind loads)-TCDL(roofing weight)-BCLL(usually 0 and not given)-BCDL(ceiling / insulation weight).

The 2x4 or 2x6 on the walls are called girts. The spacing of the purlins and girts can depend on the guage of the roofing and siding and the lumber size used. With 29g, you probably want to stick with 24" OC, but could go more with 2x6's.

More great technical info.

When I bought my first building the supplier had the forsight to ask me detailed questions about my intent, especially a ceiling. He designed my trusses to handle the weight of an added ceiling.

My roof had an overhang and he designed my rafters to sit on top of my poles giving me a 10' inside ceiling height with a 10' exterior wall height. Most designs without overhang end up with a shorter ceiling height versus wall height because the rafters sit inside the wall header and are bolted to the sides of the poles.

More things to consider.......