# Fixing into a concrete sectional garage: what actually holds

_Published by CAVE4MAN (https://cave4man.com) — storage, workshop and man-cave kit for UK home garages. The shop has not opened yet; nothing here can be ordered today._

_Updated 2026-09-19 · 9 min read_

**The short answer**

In a concrete sectional garage, the panels are thin, reinforced and unforgiving, so most loads should not hang on them at all. What works is bolting right through a panel with a large washer or spreader plate outside, fixing to the frame posts or timber wall plate, a batten spanning several posts, or a freestanding unit that touches nothing.

**In this guide**

1. [Why a sectional panel spits out fixings that hold everywhere else](https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage#why-a-sectional-panel-spits-out-fixings-that-hold-everywhere-else)
2. [Find out what you are drilling before you drill it](https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage#find-out-what-you-are-drilling-before-you-drill-it)
3. [The four methods that work, and what each one is good for](https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage#the-four-methods-that-work-and-what-each-one-is-good-for)
4. [How to bolt through a panel without wrecking it](https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage#how-to-bolt-through-a-panel-without-wrecking-it)
5. [When the honest answer is a freestanding unit and not a fixing](https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage#when-the-honest-answer-is-a-freestanding-unit-and-not-a-fixing)

## Why a sectional panel spits out fixings that hold everywhere else

The garage most people are asking about arrived on a lorry and was bolted together in a day. Its walls are precast concrete panels cast in a factory, each one a thin slab with a raised rib or flange down each edge, bolted to its neighbour through those flanges and stood on the slab. The panels get their stiffness from their shape, not their thickness. Reinforcing steel is cast in to stop them cracking in transit, and in a thin panel that steel cannot be far from either face. There is no depth of sound masonry behind the surface, which is the one thing every ordinary fixing depends on.

That is why the usual fixings fail. A plastic plug wants a deep hole in something solid; a thin panel gives it a shallow hole and daylight. An expansion anchor pushes outward against the sides of its hole; a thin panel has nothing to push against, so it spins or bursts the back face. Hammer action, right for brick and dense block, hits a thin panel from one side only, and near an edge or a joint it breaks a piece off rather than making a hole. It is a good wall for keeping rain off a car, which is all it was made for.

Pebble-dash or paint on the outside tells you nothing about the panel underneath, and a flat grey inside face can hide reinforcement a few turns of the drill down. Treat every sectional panel as thin and reinforced until you have checked, and treat the ribs, the joints and the bolted flanges as the only parts with any body to them.


## Find out what you are drilling before you drill it

A test costs nothing and saves a cracked panel. Tap the panel with a knuckle across its face: a thin section sounds hollow and rings slightly; a rib sounds dead and solid. Run a hand along the joint between two panels and find the bolts holding the flanges together, because that is where the panel has real thickness. Look up at what the roof sits on. Many sectional garages carry a timber wall plate along the top of the panels, some have steel or concrete posts at the joints, and either is a better thing to fix to than the panel itself.

Then drill one test hole, low down, in a corner nobody looks at, with the hammer action off and a sharp masonry bit. Go slowly and watch what comes out. The moment the bit skates or squeals you are on steel, and that tells you how close the reinforcement sits in this panel. If the bit goes through into daylight, you know the thickness in the field of the panel and you know that any fixing here is a fixing to the outside. Fill the hole with exterior sealant afterwards. That one hole tells you more than any forum can about a garage it has never seen.

One check comes before the drill. Corrugated cement roof sheets on older sectional garages are very often asbestos cement, and some older prefabricated garages used asbestos cement for wall panels or infill sheets as well. Asbestos cement is safe left alone and hazardous when drilled, cut, sanded or broken, because that is what releases the fibres. If the garage predates the UK ban in 1999 and you are not certain what a sheet or panel is made of, do not drill it; have it identified first and follow the advice you are given. That is not alarmism. It is the one line here that matters more than the rest.

1. **Tap the face** — A hollow ring is the thin field of the panel; a dead thud is a rib or a flange with some body to it.
2. **Find the frame** — Locate the joint bolts, the wall plate at the top and any posts at the joints. That is where the strength is.
3. **Rule out asbestos cement** — Before any drill touches an old panel or roof sheet, know what it is made of. If in doubt, have it identified.
4. **Drill one test hole** — Low, in a corner, hammer action off, sharp bit, slowly. Note where the steel is and whether the bit reaches daylight.
5. **Fill it and mark it** — Exterior sealant in the hole, and a pencil mark on the wall where the bit met steel, so the next hole avoids it.


## The four methods that work, and what each one is good for

Once you know the panel, there are four honest ways to put storage on a sectional garage wall, and the right one depends on the load rather than on preference. In rough order of how much they carry: a freestanding unit that touches nothing, a bolt right through the panel with a plate outside, a fixing into a frame member, and a batten spanning several posts or flanges so that no single fixing carries the item. Everything else, from plastic plugs to adhesive, is a way of finding out where the panel is weakest.

Notice what is missing from that list: the ordinary anchor into the field of the panel that the packaging on every wall rack assumes. A short screw into a rib will hold a clock or a light rail. It will not hold a loaded bin rack, and it certainly will not hold a bike on a rotating arm, which levers on its fixings every time the bike is swung round.

| Method | Suits | Needs | The catch |
| --- | --- | --- | --- |
| Freestanding unit | Shelving, boxes, the drawer cabinet, anything heavy | A level patch of slab; nothing from the wall | Cannot be tethered to a thin panel, so keep the weight low |
| Through-bolt with a plate outside | A tool rail, a pegboard rack, a batten | A clear hole in the field, a large washer or plate, sealant | A hole to the outside; the bolt head shows; keep clear of edges |
| Fix to the frame | Light and medium racks; the end of a batten | A timber wall plate, or steel or concrete posts at the joints | The frame is not where you wanted the rack; you go to it |
| Batten across several posts | Tool shelves, drill racks, a row of hooks | A frame or through-bolt fixing at each post it crosses | Spreads the load; does not give the panel strength it lacks |
| Plug or anchor into the field | A clock, a single light hook | Rotary drilling, a short fixing, no steel in the way | Spins, spalls or bursts the back face under a real load |


## How to bolt through a panel without wrecking it

Through-bolting is the method that turns a thin panel into a wall you can trust, because it stops asking the concrete to grip anything. The bolt passes clean through, and a large washer or a small steel plate on the outside spreads the load across the face of the panel instead of concentrating it at the edge of a hole. The item inside is clamped to the panel rather than hung off a plug in it. Choose the hole positions in the field of the panel, well in from every edge and every joint, and away from the steel you found with the test hole.

Drill it the way you drilled the test hole: rotary, a sharp bit, slowly. Go from inside, and ease off as the bit breaks through so it does not blow a cone of concrete off the outside face. Use a galvanised or stainless bolt so the head on the weather side does not stream rust down the pebble-dash, and bed the washer or plate on a bead of exterior sealant so the hole is not a drip point. Do not tighten the nut as if it were a wheel nut; a thin panel crushes under a bolt taken past snug, and once it has crushed, the clamp is gone.

Fixing to the frame is the same idea without the hole to outside. A timber wall plate takes ordinary wood screws, or a coach screw for something heavier. Steel posts take a self-drilling screw or a bolt through a drilled hole. Concrete posts are thicker than the panels and drill like dense block, but they are still a place to be careful with hammer action and edges. Whatever you fix, the rack goes where the frame is, not where you would have liked it, and that is the trade you make in this building.


## When the honest answer is a freestanding unit and not a fixing

A lot of the things people want to hang in a sectional garage should not hang on its walls at all. A parts rack with forty-eight bins full of screws, a folding bench, a bike on an arm, anything you will lean on or pull against: these are loads a thin panel was never designed for, and no method above makes it otherwise. Through-bolting spreads a load; it does not give a panel the mass of a brick wall. The building that keeps the rain off a car does not become a workshop wall by being drilled more cleverly.

A freestanding boltless shelving unit rated by its manufacturer at 175kg a shelf carries far more than any fixing into a sectional panel. It stands against the panel without touching it, goes together with a mallet and no drill, and the same manufacturer figure gives 875kg across the unit, evenly spread on a level floor. Put the 25-drawer parts cabinet on a shelf at bench height and the small fixings need no hole at all. A tall unit is normally tethered to the wall against tipping, and a thin panel is a poor tether, so keep the heavy weight low and check the slab under it with a level.

Where the wall still has to carry something, batten it. A timber batten fixed through the panel at two or three points, or to the frame at each post it crosses, becomes a length of wall you can screw into freely. A shallow four-tier tool shelf or a pegboard rack for drills hangs happily off a batten like that, and the batten, not the panel, takes the load. It also means that when the garage changes hands or comes down, what is left is a handful of filled bolt holes rather than a wall of failed plugs.

## Common questions

**Can you drill into a concrete sectional garage?**

Carefully, and only after a test hole. The panels are thin and reinforced, so drill with the hammer action off, a sharp masonry bit, well away from edges and joints, and stop if the bit hits steel. Ordinary plugs and expansion anchors do not hold in them. For anything beyond a light item, bolt right through with a plate outside, fix to the frame, or use a freestanding unit.

**How do you hang shelves in a concrete sectional garage?**

Do not hang heavy shelves on the panels. Stand a freestanding shelving unit against the wall instead; it carries more than any fixing into a panel will. For a light wall shelf, fix a timber batten to the frame posts or bolt it through the panel with large washers outside, then screw the shelf to the batten rather than to the concrete.

**Can I hang a bike on a concrete sectional garage wall?**

Not on the panel. A bike on an arm is a cantilever that levers on its fixings every time it is swung, and a thin reinforced panel is the worst wall for that. Bolt through with a plate outside only if the mount can sit in the field of the panel clear of edges, and be honest that the panel is still the weak link. A floor stand or a tension pole is the safer answer.

**Does my concrete sectional garage contain asbestos?**

It might. Corrugated cement roof sheets on older sectional garages are commonly asbestos cement, and some older prefabricated garages used asbestos cement sheet for wall or infill panels too. It is safe left alone and hazardous when drilled, cut or broken. If the garage predates the UK ban in 1999 and you are not certain, have it identified before any drill or saw touches it.

**Why does my garage panel crack or crumble when I drill it?**

Because it is thin, and hammer action loads it from one side with nothing solid behind. Near an edge, a joint or a previous hole the concrete has nowhere to go but out, so a piece spalls off. Switch to rotary drilling, use a sharp bit, keep well in from every edge, and stop if the bit hits reinforcing steel. If it still spalls, fix to the frame or go freestanding.

## Kit that does the job

- **5-tier boltless shelving, 875kg** — £49.99, not yet on sale (https://cave4man.com/product/boltless-shelving-875kg)
- **25-drawer parts cabinet** — £49.99, not yet on sale (https://cave4man.com/product/parts-drawer-cabinet-25)
- **Four-tier tool shelf** — £54.99, not yet on sale (https://cave4man.com/product/four-tier-tool-shelf)
- **Pegboard power tool rack** — £54.99, not yet on sale (https://cave4man.com/product/pegboard-power-tool-rack)

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Guide page: https://cave4man.com/guides/fixing-into-a-concrete-sectional-garage