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How to choose a joist hanger

Updated: 23 October 2026

You are measuring regularised carcassing, trimming a ceiling hatch, or framing a small timber box, and the amazon.co.uk results look like the same silver bracket. How to choose a joist hanger is a tape-measure job before it is a star-rating job. A 50 mm seat on timber that has finished near 45 mm leaves a gap, a mini on a 200 mm joist never grows a longer leg, and a woodscrew in a nail hole is not the fastener the sheet was drawn around. The eight rows, with GBP prices, are on the [joist hanger comparison](/hub/diy-supplies/joist-hanger). Updated 23 October 2026 by Peter F. We did not lab-test a joint. A qualifying purchase can earn a commission at no extra cost to you.

You are measuring regularised carcassing, trimming a ceiling hatch, or framing a small timber box, and the amazon.co.uk results look like the same silver bracket.

Our top picks

BPC Fixings BPC mini joist hangers, 47 mm, 10-piece

Best overall

BPC Fixings BPC mini joist hangers, 47 mm, 10-piece
8.4/10about £9.70
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FIXINGS DIRECT FIXINGS DIRECT mini hangers, 50 mm, 10-piece

Best value

FIXINGS DIRECT FIXINGS DIRECT mini hangers, 50 mm, 10-piece
7.5/10about £8.99
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BPC Fixings BPC standard-leg hangers, 47 mm, 50-piece

Alternative

BPC Fixings BPC standard-leg hangers, 47 mm, 50-piece
7.9/10about £41.95
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On this page
  1. 1.Measure the timber before the hanger
  2. 2.Depth and thickness are the next two lines
  3. 3.Read the coating words as printed
  4. 4.Buy the nail the hole was made for
  5. 5.Count the pieces the title actually means

Measure the timber before the hanger

The first number is the width of the piece you will hang, not the name on the stack. Regularised carcassing sold as 47 x 100 mm often finishes nearer 45 x 95 mm. A 47 mm hanger is the trade fit for that timber. A 50 mm hanger, the old 2 inch seat, leaves a gap. Once mills regularised the timber, 47 replaced 50. Sawn stock that really is about 50 mm still wants the 50 mm seat. The BPC rows here are 47 mm, and one UK review on the 10-piece says that width was exact. FIXINGS DIRECT’s £8.99 ten-pack is titled 50 mm, or 2 inch. LLB is 30 mm. Xingwenhao’s type-B bullet says an inner width of 46 mm, and one UK review measured about 50 mm inside. If you only need a conditioned pick, use best joist hangers.

Depth and thickness are the next two lines

Depth is how far down the joist the side reaches. Thickness is the steel. BPC’s mini pages say timber up to 100 mm and name ceiling hatches. The BPC standard leg, A270/47/TRADE at £41.95, prints 150 to 250 mm and a wider 50 mm strap. A mini on a 175 mm joist leaves most of the timber standing out of the hanger. The BPC 10-piece bullet says 0.8 mm and the item-depth field says 0.9 mm. The 50-piece mini bullet says 0.9 mm. BPC’s own page says 0.8 mm and G275, which is not the amazon bullet, so treat that line as unsettled. LLB prints 16.97 kN as 1,730 kg with no method. That is not a safe floor load.
BPC Fixings BPC mini joist hangers, 47 mm, 10-piece

Testsieger

BPC Fixings BPC mini joist hangers, 47 mm, 10-piece
8.4/10about £9.70
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Read the coating words as printed

Galvanised is a word unless the listing prints a zinc mass. LLB is the only row that states Z275, 275 g/m², and 20 μm. Simpson’s ETA-06/0270 and Cullen’s 2022 guide associate a Z275 minimum with service classes 1 and 2, not a permanently wet joint. Service class 3 is described as needing stainless steel, hot-dip galvanising, or a heavier coating such as ZM310, plus nails in the same metal. None of these eight listings declares service class 3 or stainless steel. BPC and AB Tools say galvanised, with no grams per square metre. The 50 mm ten-pack’s finish field says polished. Xingwenhao is black, and the colour field is Schwarz.

Buy the nail the hole was made for

None of these eight boxes lists nails or screws among the included components. BPC’s mini page names 30 x 3.75 mm sherardised square-twist nails, or 35 x 3.75 mm collated, in the holes. The standard-leg sheet uses the same family. You buy the nail beside the hanger, and you match the metal when the timber is treated. A woodscrew is the substitution fitting notes keep rejecting. UK reviews on the 50 mm ten-pack opened holes for screws, and one said the steel bends easily and will not hold a decent weight. If a page names no diameter, do not copy one from another ASIN. The sequence is on how to fit joist hangers.

Count the pieces the title actually means

Several titles and fields disagree, and UK reviews have already met short boxes. The BPC 10-piece is titled as 10. Two UK reviews were short: 8 of 10, and a single bracket. The 50-piece mini is titled as 50, and one UK review received about half the box. The standard-leg fifty arrived as 49 in one UK review. Count them on the bench before you start a run you cannot pause. The multi-truss title says a pack of 20. The unit-count field says 5. Do not divide £50.99 by either number. A star line does not count the pieces. A habitable loft, a beam, a stair, or a roof load still goes to an engineer or Building Control.

Common questions

Do I buy 47 mm or 50 mm?
Buy 47 mm when the timber is regularised and measures about 45 mm. Buy 50 mm when it is sawn at about 50 mm. The BPC rows here are 47 mm. The FIXINGS DIRECT ten-pack at £8.99 is titled 50 mm. A 50 mm hanger on 45 mm timber leaves a gap at the back of the seat.
What does regularised 47 x 100 actually measure?
It often finishes nearer 45 x 95 mm. The 47 in the trade name is the seat that replaced 50 for that finished width, not a promise that your piece is 47.0 mm. Measure the piece you will hang. A hatch trim and a joist from another pack can differ by a couple of millimetres.
Does galvanised mean Z275?
Only if the listing prints a zinc mass. Here, only the LLB page prints Z275 at 275 g/m². The other galvanised titles do not give grams per square metre. Polished, silver, and black are finish words. Z275 is associated with service classes 1 and 2, not with a wet deck.
Which nail fills the hole?
Where a BPC sheet names one, it is a 30 x 3.75 mm sherardised square-twist nail, or a 35 x 3.75 mm collated nail. You buy it separately. These boxes do not include it. If the listing prints no diameter, do not copy the nail from a different ASIN and assume the hole matches.
Are nails in these amazon.co.uk boxes?
No. Included components name the hangers, or in one case a case. Pages that ask whether screws are included do not answer. UK reviews that describe fixing are using nails or screws the buyer supplied. A short hanger box and a missing nail box are two separate stops.
Can I trust 1,730 kg on the LLB listing?
No. The page prints 16.97 kN and equates it to 1,730 kg, with no standard and no nailing schedule. The seat is 30 mm, so the figure is not a capacity for a 47 mm joist.

Related pages

Joist hangers for decking

Mini joist hanger vs standard

Joist hanger

Best joist hangers for a UK hatch or a shallow joist

How to fit joist hangers and fill every named hole

Sources

Public UK sources and the amazon.co.uk listings compared on this page. Listings captured 21 October 2026. Updated 23 October 2026.

  1. Simpson Strong-Tie hanger installation (retrieved 21 October 2026)
  2. BPC mini hangers (retrieved 21 October 2026)
  3. BPC standard timber-to-timber hangers (retrieved 21 October 2026)
  4. Cullen technical guide 2022 (retrieved 21 October 2026)
  5. ITW EC5 guidelines (retrieved 21 October 2026)
  6. Approved Document A (retrieved 21 October 2026)
  7. CPA loft conversion project guide (retrieved 21 October 2026)
  8. HSE working at height (retrieved 21 October 2026)
  9. PBC Today: joist hangers (retrieved 21 October 2026)
  10. Arras CF joist hanger ETA (retrieved 21 October 2026)