What to Know Before Building a Pole Barn: 5 Details

Every item on this list is cheap before the build and expensive after it. An owner walked his finished pole barn on camera and pointed at the things he wishes he'd asked about, and not one of them is structural. They're small decisions made in the weeks before a crew shows up, by whoever thinks to raise them.

The video is titled four tips. There are five things in it.

1. Drainage gets decided before the pour

He starts with drainage, and he can point at it: a drain in the floor, and a pipe running underneath the concrete to carry the water off.

Both went in before the slab. That's the entire point. A floor drain is rough-in work, not a fixture, and once the concrete has cured, adding one means cutting up the floor you just paid for.

So decide early whether this is a building that ever gets wet inside. Livestock, equipment wash-down, a shop floor you hose out. If the answer is maybe, the rough-in is far cheaper than the retrofit.

Concrete is already one of the largest single items in a post-frame build. In the pole barn cost guide, a builder itemized his slab at $7,000 out of about $31,000 for a 30x40. Sawing into that later to chase a drain line is not a small job.

2. Say the word gutters before the roof goes on

This is the one most people won't see coming. His crew told him afterward that they would have cut the roofline back about two inches so the gutters would fit.

Read that again. The roof isn't wrong and the gutters aren't unavailable. The panels simply run two inches further out than they would have if anyone had known gutters were coming. Hanging them is now a trimming job on a finished roof instead of a detail handled on the ground.

Gutters are also the item most likely to fall out of a quote quietly. They aren't part of the shell and they're rarely in a base package. Mike, in our pole barn chicken coop guide, is a year into his building and paying someone to come add them on both sides, because runoff off a bare roof was kicking mud back toward his door.

Two owners, two buildings, one regret.

3. The bottom plate needs a seal

Next he points at the bottom plate, the framing member sitting directly on the concrete, and says to make sure it's going to have a seal on it.

That joint runs the full length of every wall. It's a continuous gap between wood and concrete, and it's the path of least resistance for air, for water wicking up out of the slab, and for anything with six legs.

Sealing it costs very little while the wall is still open and the crew is standing there. After the siding is on and the inside is finished, you're working blind at a seam you can barely reach.

4. Flashing where the concrete meets the building

Same seam, outside face. He says to double check that the bottom has flashing where the concrete meets the building.

Flashing at the base throws water out and away instead of letting it run down the wall panel and sit in the joint. Steel siding that dead-ends at a slab edge with nothing covering the transition gives water a straight shot at the framing behind it.

Want a fast way to size up a builder? Walk the base of one of their finished buildings. This detail is visible from the outside, on any barn they'll point you at as an example of their work, which makes it one of the few quality signals you can inspect yourself before you sign anything.

5. Ask what the trusses can do

The last one is the one he sounds most annoyed about. He learned after the fact that a snoot truss existed, and that he could have asked for it.

A snoot is an overhang detail. The truss carries the roof out past the sidewall instead of stopping flush with it, which buys you an eave, a place to hang a soffit, and a roofline that throws water further from the wall.

Whether you want one is part looks and part function. The problem is timing. Trusses get ordered and built to spec well before a crew shows up, and it isn't a change anyone makes on site with a saw. If nobody puts the options in front of you, you get the default and find out later there was a menu.

What all five have in common

None of these is a repair. They're decisions, they all get made before anything is ordered, and every one of them is cheap on paper and expensive in the field.

Notice what isn't on his list. Nothing about post spacing, truss capacity, or whether the building is standing straight. The shell was fine. The same pattern runs through the chicken coop guide: the structure is not what people regret. They regret the edges, which is to say where the water goes and what got specified.

The questions to ask before you sign

Bring these to the walkthrough, before the truss order goes in.

1. Where does the water go, inside and out? Floor drain, pipe under the slab, and the grade around the building.
2. Are gutters in this quote? If they are, confirm the roofline gets set up to take them. If they aren't, say out loud that you may add them later, and ask what changes today.
3. How is the joint between the slab and the bottom plate sealed? Ask what material, not whether.
4. Is there base flashing where the concrete meets the wall? Ask to see it on a building they've already finished.
5. What are my truss options, and when does that order lock? Overhangs, snoot, soffit. Get the deadline, not just the menu.

A builder who answers all five without hedging is telling you something useful about how they work. So is one who can't.

None of this moves the price much. All of it changes the building.

Find a builder who'll walk the details with you

The five questions above work best in person, standing on the site, before anyone orders material.

Ask before the order. Inspect before the pour. Everything after that is a repair.