Make life easy, search the forum.

joists

A joist is a horizontal structural member used in framing to span an open space, often between beams that subsequently transfer loads to vertical members. When incorporated into a floor framing system, joists serve to provide stiffness to the subfloor sheathing, allowing it to function as a horizontal diaphragm. Joists are often doubled or tripled, placed side by side, where conditions warrant, such as where wall partitions require support.
Joists are either made of wood, engineered wood, or steel, each of which have unique characteristics. Typically, wood joists have the cross section of a plank with the longer faces positioned vertically. However, engineered wood joists may have a cross section resembling the Roman capital letter "I"; these joists are referred to as I-joists. Steel joists can take on various shapes, resembling the Roman capital letters "C", "I", "L" and "S".
Wood joists were also used in old-style timber framing. The invention of the circular saw for use in modern sawmills has made it possible to fabricate wood joists as dimensional lumber.

View More On Wikipedia.org
  1. P

    4 1/4" hole in 2x10 floor joists

    i noticed when removing some subfloor that the builders placed a 4 1/4" hole for a toilet waste pipe in 2 floor joists on the second floor. the joists are 2x10 and the span is 27'. the bottom of the hole is 1" from the bottom of the joist. i have been asked to tile the floor of this room with...
  2. P

    My 1st Job Tanking details: Wetroom floor on joists with flush linear drain and wet UFH.

    Hi, I'm new to the forum (and tiling / bathrooms) and appreciate the many threads that I have been learning from. If anyone had a moment to comment on the tanking and drain plan for my new attic wetroom I would be very grateful. I'm doing all the work myself, learning as I go. I'm most...
  3. Mmark

    GifaFloor FHB18 Joins without Joists and no Edge Support.

    We have a 4x3 bedroom with the following 12 spans: 190, 368, 380, 365, 380, 370, 385, 370, 395, 385, 370, 300 The UFH was installed by builders ready for the GifaFloor FHB18 (18mm). FHB18 is rated at 2kn point load when installed to manufacturers instructions, they estimate to reduce that by...
  4. Sean Kelly

    Wet UFH in screed, between joists covered with ply.

    Wet UFH in screed, between joists covered with ply. Is this a thing? I got a call the other day from a builder describing the above. He wants it tiled asap. I wont go and see it until the ply is down plus its a 40 mile round trip to the house. English is not his first language and it was...
  5. D

    Install 18mm ply between joists

    I would like to Tile my hallway and need to minimise the impact this will have on the finished floor level, to provide a smooth transition to an adjoining room. Do you think it would be acceptable for me to do the following: - Remove and discard the existing floorboards. Fix 70mm X 20mm...
  6. F

    Floor prep for screed inbetween joists

    Just a quick one guys, a job in the pipeline, I've been asked about the prep that will be required, here's the scenario.. 70m total area ish New extension with new screed (50 - 60mm) and ufh. Existing building with joists, the floor boards are coming up and the ufh is being fitted between...
  7. 1

    Subfloor build up on timber joists.....

    Hi all, After a bit of advice on subfloor build up if those in the know could help out? Am in the process of renovating my bathroom in my Victorian terrace - approx 8m2, floorboards have been lifted for fist fix plumbing (not re fixing as they're in a state) My thoughts on subfloor for...
  8. S

    Preparation Underfloor heating between joists

    Hi all Just looked at a job where builder wants to put down 22m chipboard over joists then Ditra. I said nooooo. The heating system is wet on a polystyrene board with aluminium trays screwed to joists. I have mentioned giffa flooring. The joists are 400 centres so could probably use the 18mm...
  9. M

    Wet room construction over joists with wet underfloor heating

    Hi, First time here and hoping this is an easy question! I am installing a wet room upstairs and going back to joists but I also want to install low profile wet underfloor heating (I already have it), what will give me the best surface to tile on and support a bath on top? So I was planning...
  10. B

    No more ply and wet system UFH sat within joists - efficiency concerns...

    Apologies this is so long winded, but hopefully you're an understanding bunch & you'll stick with the novel and provide a straight opinion on this. I'm a competent DIY'er (ex-spark), but it's a while since I've done any DIY tiling at home. I'm now re-doing the kitchen floor/walls in a 1960’s...
  11. CJ

    Preparation Tiling over wet UFH between joists

    I need to quote for a job, as the title says........over wet UFH between joists. Much the same as the link I've put up. Insulation, fitted between joists.....pipes laid, maybe with or without spreader plates. (Not sure as yet which way customer is doing this) then the floor would be overlaid...
  12. S

    Setting Out 22mm ply onto joists, ufh, which board to use and why?

    Hi all, been browsing through the forum trying to find a definitive answer. I'm in the process of qouting for a 33m2 floor. The floor is not ready yet, but it will be 22mm wbp plywood primed on all surface and then down directly on to the joists, noggins will be added and bricks built up under...
  13. M

    Tiling in a room with suspended and concrete floor, with under floor heating

    Hi. We are tiling a ground floor kitchen that is half suspended floor (100x50 joists on 300 spacing, with supports every 1200mm) and half concrete slab. The concrete slab has just been poured and once insulation has been added, it will have UFH pipes buried in the screed top layer. The tiles to...
  14. Lakey

    Preparation Boarding between joists

    Happy New Year everyone! Just wanted to check the feasibility on a shower room floor prep. A customer has asked me to tile (walls & floor) in an ensuite shower room. She is quite uneasy on her feet so wants the transition between the bedroom carpet & the ensuite tiled floor to be as level as...
  15. C

    Water UFH Wet UFH on Block & Beam and Joists...

    Hi everyone, We've an existing kitchen floor on Block & Beam + starting an adjoining extension with wooden joists. (has to be due to slope) We are wanting 'Wet UFH' across both surfaces finished off with tiles but only have a maximum height on top of block & beam of 80mm (including tiles), is...
  16. J

    Replace floorboards with Ply or put back down and Backer board - after replacing floor joists?

    Existing floor covering is 18mm T&G floorboards. If you had to replace some floor joists, and to re level some floor joists, would you: 1. bin all the floorboards that have to get removed to fix the floor. replace the floorboards with 25mm wbp ply and tile directly onto that. or 2. bin all...
  17. P

    Tiling Over Joists.

    Hello, we've just bought a new house, the current ground floor is concrete and I'm thinking about installing under-floor-heating. I don't want to screed as the reception room areas are too large, (16 2m each of 2) so I was thinking of putting down a DPM with 4x2 sawn battens (at 400mm...
  18. J

    Water UFH Pug/bisuit Mix For Ufh, Timber Joists, Wet Or Dry

    We are doing wet UFH on suspended floors with very strong timber joists (9 x 3in at approx. 400mm centres, max span 4.8m). We are setting the pipes between the joists on a 45mm thick PIR base and pug mix (8:1 sharp sand: cement) between and around the pipes, as commonly used. I understand the...
  19. A

    Tiling Onto Timber Floor With 4 Inch Joists

    I'm intending to tile a kitchen diner floor, 1/3 of which is concrete but the other 1/3 a suspended timber floor on 4 inch joists. I'm aware that such joists have a propensity for deflection/bounce, which I need to remove. My intended plan of action is to remove all the floorboards and replace...
  20. P

    Builder recommends I replace all joists before tiling!

    Hi there, fantastic forum by the way guys! I've just had a large kitchen/diner extension built. It is made up of three parts 1) The original Edwardian house with suspended wooden floor 2) An extension built about 7 years ago with solid floor 3) Extension built now with suspended timber...
This website is hosted and managed by www.untoldmedia.co.uk. Creating content since 2001.

UK Tiling Forum Stats

Threads
66,600
Messages
866,704
Members
9,511
Latest member
mmcdon47
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock