A heavy duty cardboard box is a double wall box: corrugated board with two layers of fluting, where an ordinary single wall box has one. How strong the box turns out to be in use depends on the board, the size of box you choose for the load and how you tape the base.
This guide explains what makes a box strong, when double wall is worth paying for, and which size to use for books, tools, kitchenware, stock and parcels going abroad. It then covers the tape to use, how to pack a heavy box so the base holds, and how to buy.
In This Guide
- Quick picks for heavy and fragile loads
- What makes a cardboard box heavy duty?
- When do you need double wall boxes?
- Which size heavy duty box suits books, tools and kitchenware?
- Are heavy duty boxes worth it for international parcels?
- Which heavy duty box tape should you use?
- How do you tape and pack a heavy box so the base holds?
- How many strong boxes should you buy, and what do they cost?
- Frequently Asked Questions
Quick picks for heavy and fragile loads
A strong box, a wide tape and a roll of cushioning cover most heavy packing jobs.
Best for heavy, fragile and high value loads
Double Wall Cardboard Boxes
Corrugated boxes with two layers of fluting, supplied flat and sold per box.
- 11 sizes, 9 x 6 x 6" to 24 x 24 x 24"
- Minimum 5 boxes for most sizes
- Price per box falls as you buy more
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView product
Best for sealing heavy cartons
Brown Packing Tape
Buff polypropylene packing tape, including the wide Proloc roll for bigger and heavier boxes.
- Proloc 72mm x 66m, the widest roll we stock
- Standard 48mm rolls are 42 micron acrylic
- Packs of 6 rolls
From £4.50 ex VAT (£5.40 inc VAT)
Choose sizeView product
Best for cushioning bulky breakables
Large Bubble Wrap
Bubble wrap with 25mm bubbles that also works as void fill in a large box.
- 25mm bubbles
- 300mm or 500mm wide
- 50m per roll, sold per roll
From £9.00 ex VAT (£10.80 inc VAT)
Choose sizeView productWhat makes a cardboard box heavy duty?
The number of fluted layers in the board is what makes a cardboard box heavy duty. Fluting is the wavy paper sandwiched between the flat liners. A single wall box has one layer of it and a double wall box has two, so the double wall board is thicker and stiffer, and the box stacks better.
Our double wall cardboard boxes are the heavy duty boxes in the range. The lighter option is our single wall cardboard boxes, which suit everyday online orders, storage and light moving. If you want the two board types compared side by side, read single wall vs double wall cardboard boxes.
No weight ratings here. We do not publish a kg limit for any box because we have no tested rating to give you. The practical rule is that heavy things go in small boxes, and a packed box should be one you can lift without straining.
When do you need double wall boxes?
You need double wall boxes when the contents are heavy, breakable or expensive, or when the box will be stacked, stored or handled many times. For light goods that fill the box and travel once, single wall is enough and costs less: our single wall boxes start from £0.35 ex VAT (£0.42 inc VAT) against £0.59 ex VAT (£0.71 inc VAT) for double wall.
| Job | Board to choose | Why |
|---|---|---|
| Clothes, soft goods, light boxed products | Single wall | Little weight on the base, and the contents cannot break |
| Books, tools, tins, metal parts | Double wall | Dense loads put the base and the seams under strain |
| Crockery, glasses, ornaments | Double wall | A stiffer wall gives the cushioning something firm to work against |
| House move with stacked boxes | Double wall | Boxes are stacked in the van and lifted several times |
| Export and long distance shipping | Double wall | More handling points and more time in transit |
For how many boxes a house move needs, see our moving boxes guide.
Which size heavy duty box suits books, tools and kitchenware?
Pick the smallest box that holds the item and its wrapping, and put the heaviest things in the smallest boxes. A big box filled with books is a bad idea however strong the board, because nobody can carry it safely.
| Load | Double wall size to start with | Packing note |
|---|---|---|
| Small heavy parts, fixings, hand tools | 9 x 6 x 6" (229 x 152 x 152mm) | The smallest size. Wrap sharp edges so they cannot cut through the board |
| Documents, boxed goods, stock for posting | 12 x 9 x 6" (305 x 229 x 152mm) or 12 x 9 x 9" (305 x 229 x 229mm) | An A4 sheet (210 x 297mm) lies flat in the base |
| Books, tins, records | 12 x 12 x 12" (305 x 305 x 305mm) | Lay books flat and stop filling when the box gets hard to lift |
| Kitchenware, pans, small appliances | 14 x 14 x 14" (356 x 356 x 356mm) or 18 x 12 x 11" (457 x 305 x 279mm) | Heaviest items at the bottom, cushioning between each piece |
| Bedding, cushions, lampshades | 24 x 18 x 12" (610 x 457 x 305mm) and larger | Bulky, light things only |
Keep the three largest sizes, up to 24 x 24 x 24" (610 x 610 x 610mm), for light loads. For more on the big sizes, see large cardboard boxes: sizes, strength and best uses.
Best for books, tools and breakables
Double Wall Cardboard Boxes
Heavy duty corrugated boxes with two layers of fluting, in sizes from small parts boxes to extra large moving boxes.
- Supplied flat, sold per box
- Mix sizes on one order
- Minimum 5 for most sizes, 90 for 24 x 24 x 24"
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView productAre heavy duty boxes worth it for international parcels?
Yes, a double wall box is the safer choice for a parcel going abroad, because the parcel is sorted, stacked and reloaded more times than a UK delivery. Export and long distance shipping is one of the common uses for our double wall boxes.
- Size the box to the goods. Empty space adds to the parcel size and needs more void fill.
- Check the limits before you pack. Maximum weights and dimensions differ by carrier and destination and they change, so check the carrier for current limits.
- Seal every seam. Use the H pattern on the top and the base, described below.
Which heavy duty box tape should you use?
For heavy boxes, use a wide polypropylene packing tape and more than one strip on the base. In our brown packing tape range that means Proloc 72mm x 66m, the widest roll we stock. It is close to a 3 inch tape and covers more of the seam in one pass.
The standard 48mm x 66m and 48mm x 132m rolls are acrylic polypropylene on 42 micron film and are fine for most boxes if you add extra strips across a heavy base. All five brown tapes come in packs of 6 rolls, from £4.50 ex VAT (£5.40 inc VAT) per pack. If the box holds breakables, fragile tape seals and labels it at once.
A tape gun makes it easier to pull the tape tight along the seam. Match the gun to the tape width: of our pistol grip tape gun dispensers, the PG75B takes 75mm tape, so it is the one for the 72mm Proloc roll. The PG50B, the heavy duty Pacplus HPG50B and the Big Tape 2in1 Core take 50mm tape, which suits our 48mm rolls. Guns are sold individually from £5.00 ex VAT (£6.00 inc VAT).
How do you tape and pack a heavy box so the base holds?
Tape the base in an H pattern, put the heaviest items at the bottom, fill the gaps, and stop adding weight while you can still lift the box comfortably.
- Fold the base flaps square. Short flaps in first, long flaps over them, with the edges meeting in the middle and no gap.
- Tape the centre seam. Run one strip along the join and carry it up each end of the box.
- Finish the H. Tape across both short edge seams where the flaps meet the box sides. The three strips form a letter H.
- Add a second centre strip for dense loads. On a box of books or tools, lay another strip over the centre seam, or use the 72mm roll.
- Cushion the base, then load heavy to light. Put bubble wrap or scrunched paper down first, with the heaviest items flat on the bottom and lighter ones on top.
- Fill the gaps. Contents should not move when you shake the box gently. Fill to the top so the lid is supported when another box sits on it.
- Lift before you seal. If the box is a struggle, take something out and start a second box. Then close the top and tape it in the same H pattern.
For cushioning bulky or heavy items, large bubble wrap has 25mm bubbles and comes on 50m rolls, 300mm or 500mm wide, from £9.00 ex VAT (£10.80 inc VAT). Smaller, delicate pieces are better in small bubble wrap with 10mm bubbles. On a house move, newspaper or old towels fill gaps just as well and cost nothing. The full method is in how to pack a box for shipping, and the other fill options are in our void fill comparison.
How many strong boxes should you buy, and what do they cost?
Double wall boxes are sold per box from £0.59 ex VAT (£0.71 inc VAT), with a minimum of 5 boxes for most sizes and 90 for the 24 x 24 x 24" size. You can mix sizes on one order, and the price per box falls as the quantity rises. The tiers are shown on the product page.
- One house move. Order more small and medium boxes than large ones, since most heavy household items belong in the smaller sizes.
- Regular stock shipping. Settle on one or two sizes that fit your products and buy those in quantity to reach the lower price tiers. Regular buyers can apply for a trade account.
Royal Mail Tracked 48 delivery is free on every order with no minimum, and orders placed by 2pm Monday to Friday leave our Manchester unit the same working day. You can also click and collect free in Manchester, usually within 2 hours, or use same-day van delivery within 10 miles of Cheetham Hill. Browse all cardboard boxes, packing tapes and protective packaging, or contact us on 0161 706 1246 if you are unsure which size fits.
Frequently Asked Questions
What are heavy duty cardboard boxes?
Heavy duty cardboard boxes are double wall boxes, made from corrugated board with two layers of fluting. A single wall box has one layer. The extra layer makes a double wall box stiffer and better at stacking, which suits heavy, fragile or high value contents.
How much weight can a heavy duty cardboard box hold?
Pack Solution does not publish a weight limit for its cardboard boxes because there is no tested rating to quote. The practical rule is to put heavy items in small boxes, keep each packed box light enough to lift comfortably, and tape the base in an H pattern. If a box is hard to lift, split the load across two boxes.
What are the best strong boxes for moving house?
Double wall boxes are the best strong boxes for moving house because they are stacked in the van and lifted several times. Use 12 x 12 x 12 inch boxes for books and other dense items, 18 x 18 x 18 inch boxes for general packing, and 24 x 18 x 12 inch boxes or larger for bedding and other light, bulky things.
What is the best tape for heavy boxes?
The best tape for heavy boxes is a wide polypropylene packing tape applied in an H pattern across the base. Pack Solution's widest roll is Proloc brown tape at 72mm x 66m, sold in packs of 6. A standard 48mm packing tape also works on a heavy box if you add a second strip along the centre seam.
Can you reuse a heavy duty cardboard box?
You can reuse a heavy duty cardboard box if the corners are still firm, the board is dry and the flaps have not torn at the folds. A box that has been crushed, creased or damp has lost stiffness, so keep reused boxes for light loads. Use a new box for anything fragile, valuable or going abroad.
