Mate, this is the most comprehensive ‘how to’ I’ve seen on RU-vid. Love that you cover the ‘why’ of the decisions you’ve made along with the other options available. Thank you
From a fellow over-enthusiastic DIYer, I can't praise this video series enough. Impressed by the amount of research you have done and the knowledge you've gained. Love the level of detail, the explanations, the commentary, how informative they are - love it all....except for the music of course! 🤣
Hi Ali, You are amongst a few amateur DIY builders who explain everything in its most practicable form. I've watched from part 1 to part 6, and i feel confident that with your advise and instructions i can follow what you have made. Thanks for making it easy for us all. Keep up the good work.
Thanks Tony, they were a bit sketchy editing wise at the beginning but glad the info has come through clear. This is a very doable project with a bit of thought and planning :)
This video is (the whole garden room/workshop videos) about 3 years old but still the most comprehensive video on RU-vid. Going to start my project soon and i am a novice at this but your videos have truly inspired me to do it myself rather than getting someone in to coming in a doing it. My project will be smaller as i am looking at 4m x 3m but some great ideas between you and 'rag n bone brown'. thanks
What a fantastic tutorial, these videos have given me the confidence to have a go at a much smaller but similar project. Thanks for taking the time to make these videos to such a high standard.
Amazing helpful job. Thanks for all the details mentionned. I'm going to do approximatly the same for a 4 by 4 meter tiny house. I think I'll use a 45 x 120 mm that should be enough.
This was just what I've been looking for. I'm about to pull up my floorboards, level everything, and then install the insulation and plywood as you did here, before replacing the hardwood on top. It seems that every video I've watched up until this point left out something! Thank you very much!
I've been a carpenter/joiner/cabinet maker for over twenty years and I have to say for a lay man you have good skills. I build a 500 sq ft workshop in much the same style as this.
Your videos are fantastic. I've been watching videos on garden room building for a long time now as I want to build one also. Your videos are by far the best I have seen. My main concern was how to approach the foundations and floor structure. Your videos have helped allot with that. So Thankyou and please keep them coming. Looking forward to the next one!
(In case it's of use to others who go down the rockwool insulation under the floor. I found a tarp worked well. You have to drape it over the joists though and support it underneath. If I made my shed again I would use celotex type insulation but its was not so easily available 20 years ago. I would like to say thanks to Ali, so informative. I'm going to build an extension soon. The way its been built so well on a very tight budget is just the impetus I need.
Been looking through RU-vid for some real guidance on building my cabin. Was looking for how to create the timber frame. Your videos and in depth explanations are excellent. Thanks.
We were planning a garden office / shed area in a L-shaped formation and although we are complete novices we (well the other half) is very hands on when it comes to DIY. We watched 00s of online videos but nothing comes close to the comprehensiveness of these videos! So informative, well thought out, easy to follow and tbh, it has inspired me to get my hands dirty (will have to do the nails later!). Ali, thank you, subscribed and really looking forward to watching all the videos. Thank you again!!
That's fantastic Tahera. It's great fun, especially if you do it with your other half, and will save you a ton by doing it yourselves. Thanks for the comments too!
Absolute legend the girlfriend and I wanted a extension on the house but found it will be cheaper to jst build a summer house down the bottom of the garden and your videos are exactly what I have been looking for can't wait to see it done. Keep up the good work buddy cheers.
I've just started looking at building something similar and have to say thus is the most comprehensive guide I've seen to date! You've already answered most of the questions I've had, thank you very much.Well done!
Great video series Ali. Just one thing for people to be aware of and that is that you don't get the insulation benefit from the aluminium foil covering of Celotex unless you have an air gap between that reflective cover and the next material. So where you lay the plywood directly on top of the Celotex you aren't getting that benefit from the product but you are still achieving the "U" values you were after. The reflective benefit can come in cavity walls where there is still an air gap between the Celotex and the brickwork.
Thanks Neil. The main reason for taping the floor was a vapour barrier but had hoped it would reflect infrared radiant heat back towards the building too. Do you know why it need the air gap around it exactly?
Ali Dymock yes it is back to your GCSE Physics lessons on heat transfer. Essentially three types Conduction, convection and radiation. Conduction is the most efficient so when things are touching then this will be the primary form of heat transfer. With your celotex it is touching the reflective surface which is touching the ply which is touching the flooring so the heat will move backwards and forwards through the materials via conduction. For the reflective/radiant barrier to be efficient at all and not dominated by the convection then you need to break the conductive link. You do this with an air gap minimum an inch. This allows the reflective material to reflect the radiant heat back. You can test this with a frying pan on the stove. Obviously if you put your hand on it it will burn if you put your hand six inches away you will feel a strong heat but if you put a bit of tin foil in between you won’t feel the heat. Put the tin foil directly in the pan and it conducts the heat like the rest of the pan and your hand will feel hot again! The celotex and tape does a good job as a vapour barrier though and the celotex as a pure non-conductive material does a good job too.
@@neiljpearce This is interesting and too late for my build as my floor has been constructed using Ali's videos as an instructional guide. Neil Pearce - if I apply your method to my walls, won't I need some form of ability for air to actually get INTO the walls to circulate in the first place? I've not even bought any PIR for my walls yet as I'm waiting until I've routed my cabling for electrics, but I too have used 4x2 stud walling. The 4x2 actually measures a depth of around 95mm so was intending buying 90mm PIR, however, based on your info I would need to go a lot thinner than that to gain a sufficient 'gap' for air, and then I would need to look at how I get air into the walls to circulate like the roof. I'm using your 'air gap' method for my 'cold roof' system (unlike Ali, I don't have the ability to build up to use a 'warm roof' option due to Permitted Developments), and will have vents at the front and back between my roof joists and the gap over my PIR for air to circulate.
Great set of videos, just embarking on a garden office build in light of the current Pandemic, not in the building trade myself, but these videos make it understandable - about to complete the floor and move on to Part 7 - Many, many thanks...
That's great to hear Ian! Defo watch all the way through the series before starting as everything in the build is interconnected and there are lessons later on which apply here.
@@AliDymock yeah have watched right through a number of times and make a work breakdown and checklist as I go through so as hopefully not to miss anything. BTW: Did you make a video that covered cladding the building. Thanks again...
Hi Ali Paul again very impressive workmanship and attention to detail again in this video plywood was for sure your best option for this as a finished floor as osb doesn't have as nice of a flat nice surface and plywood is a better overall finish i also like the way you done your jig for fitting your insulation also i would like to note you done a good job using the expanding foam a lot of tradesmen would not have went to the effort of doing that so well done there really enjoying your progress and attention to detail brilliant.
I’m hooked watching these. Feeling very inspired to also build one of these perhaps on a slightly smaller scale. Thank you very much for all your clear and insightful videos. Much appreciated.
This is so informative and very clearly explained. I also appreciate all the maths and wise words of precautions on various points. Looking forward to seeing more as this is pretty much the kind of thing I want to build too, although it will be on a slight slope.
Great videos, I've nearly finished my (tiny) garden room but i WISH I'd seen these earlier....builders assume you just know all this stuff! very informative, thanks
Watched all your vids, very informative and by far the best vids of this type I've seen so far and I've watched many to get an idea how to build my shed... Keep it up mate. Look forward to the next one....
Just for future reference, OSB 3 is more weather resistant than ply, and if taped also acts as an air barrier. Although unless treated with an anti slip coating, it is lethal for flooring in wood workshops when sawdust is on it. :o
Definitely protect the exposed cut edges of the flooring, on all edges! Especially as the external walls are going to sit on the flooring?? Also, no need to leave gaps on the flooring sheets. Plywood is STABLE and does not expand and contract - due to 90° thin layers and glue. Brilliant series. Just come across your series, and loving it. Going to binge the lot!😂😂 Selling my house to buy something run down to do up, and set up my own garage workshop like this. Great series! Would it be worth revisiting with new cost options? One thing i didn't understand from early permitted developments - how can you have a 3m roof mono pitch, with a max 2.1 ceiling joist? 3m back wall to a 2.1m front wall, with sloping roof?? Also, from memory where is datum taken from to measure heights?? My back garden slopes up from the house!🙄
Agree with all the comments here, really informative vids so thank you! - considering there are so many people doing something similar it’s surprising how little decent info there is out there. A lot of it seems to contradict each other, especially regarding breathable membranes for walls, so looking forward to seeing how you went about that?
It's a popular trend right now for sure! There is some wrong info out there but a lot of it is subjective and there's no right way, so it's best not to get hung up on it. Other than the foundations I'm building mine properly, like they build a house in the US, with few shortcuts or cost savings but everyone has a different need so there's little wrong with doing things differently. No doubt as more people find this video there'll be people disagreeing with this or that. As for the breathable membrane-see sneak peak in Part 3-you can see the Tyvek housewrap - proper stuff!
Thank you Ali for these wonderful detailed videos of your garden room. Just about to start a very similar build and the information you have shown helps and supports my thinking brilliantly. Looking forward to the remaining videos. Regards
Really informative Ali, and thanks for including the costing diagrams, there are so many different options here in the UK and trying to weigh up cost against suitability is sometimes tricky. I am in the process of buying a new home, specifically chosen, as it excitingly, comes with a big double garage. Whoop! I really am excited as my current workshop is comparatively small. My plan is to build within a freestanding workshop and I have been researching the most cost effective insulation types, so a big thanks again, your experience here is a great help. I continue to be impressed by your workmanship, especially that snug fit cut, nice. How’s the new job going? Be sure to let me know if it falls through, I am known to make a cracking cup of builder’s tea! Btw, I do hope to see more from you here after the build is complete, your videos are interesting, fun and I am learning a lot. 👍🏼
Looking at my channel statistics, I think you're one of only a few women who have watched my videos! 😂 That sounds very feasible-by attaching timbers to the walls of the garage and then insulating in-between you'll be able to work in there all year round. Regarding workmanship- even if you pay an expensive builder firm, they won't take the care getting things like insulation nice and snug, so even though it was my first time doing it I know I get a better finish doing it myself. Job is going very well-sorry! Though if you lived nearby, happy to trade ideas for tea!
great series, I wish I had seen this a few years ago, I have a steel shed I need to insulate and thinking about the options on the concrete floor and whether I need the walls and roof to be cold , or fully insulated, and the moisture requirements .
I wonder if you're THE Martin Freeman and are planning to build yourself a hobbit hole... I've put the time of year in the videos so you can see how quickly I got things done but as you say, it will vary from person to person and different projects and building methods. As for costs, I'll do a budget video at the end and then update the descriptions in each to say how much it cost to get to each stage :)
This is excellent, i havent watched them all yet and i can already say this is spot on! Im looking to building a mini garden house/ log cabin as i need an office. Kids are pushing me out of my current office. The attention to detail is exactly what people need. Well done to you! One of the decisions i am trying to answer is the type of floor. Concrete slab or what you have done here.
Glad it's helpful. No doubt you'll build it and the kids will decide they want it instead! Yeh, it's a toughy. I decided against a slab as my original one cracked, the site is surrounded by trees and on clay and it's also sloped. But I do think a slab is a good way to go 👍
Yes! i can imagine it wont be my office for long! Did you find any good advice on slabs? i have helped my dad do loads of shed slabs but for mine i wish to add insulation but am struggling to work out how this works without a course of bricks around the edge...
Well you can embed the insulation in the slab or you can have a timber frame sat on top of the slab containing the insulation. The latter is the normal route for anything other than extensions etc.
Thanks for the reply! I was thinking the latter as when we embedded the insulation in the oversight(extension on house) we had the bonus of bricks and blocks to damp level. I guess ill get the slab done, then a wooden frame on top like you did for your floor. Then build the cabin on that.
As a carpenter of over 20 years of experience, the most significant risk of doing this way is that you create a condensation on the surface of the insulation that you are using and the plywood, which it’s called interstitial condensation. The condensation of course will give you mould forming and potential health problems. Without mentioning that this will damage throughout time the floor deck structure and plywood floor. Avoiding the risk of condensation can be very complex as a wide range of variables come into play. My advice is never put insulation on floor as its the foundation of the shed. Also it does not add any extra values.
Hi Ali, I love this series of videos, you've inspired me to build a Log cabin at the end of the garden and I'll be using the same "Block and wooden frame base construction as you. In this video you mention about not using Chipboard Flooring but, don't give a specific reason why? I was thinking of using Egger Protect Coated weather Resistant Chipboard flooring.
Yes I was thinking the same. I will be using a DPM over the top to keep it dry until I have my roof on. Egger protect is no longer available that’s y I’m using a different brand but keeping the DPM on it
Hi Ali, Enjoying the videos. I am just going to construct a garden room. I am going to construct a floor like yours but concerned about rodents getting into the PIR from underneath.
It seems you've defeated the purpose of the adhesive as you are simply gluing the plywood to the tape and not the joists. That joint is now relying on your fasteners and the strength of your tapes adhesive, the caulking is moot.
Hi, excellent video series, I was curious that the underside of your floor insulation was exposed are you not concerned about moisture or rodents getting into the PIR? Thanks
Cheers Richard. Moisture: - nope, the space below allows air flow to remove moisture, just like in a house Rodents: - again no, they don't really get into PIR and would struggle to climb up there. It's honestly no different to how a house's floor is made (just better insulated!)
I can see from the last pic of the vid, the build is wet from rain by the looks of it. Are the materials used in the vid generally OK to be outdoors and exposed to the elements for a short time? I'm considering my own build and curious about how long I have to put into it before erecting a roof to help keep the bulk of rain away
Great video series. I am using your videos and principles used to build a glamping pod. Can I ask why you say 'don't use chipboard' for the floor? Thanks in advance.
Hello Ali, I’ve watched your vid numerous times and yep you’ve convinced me to give it a go myself.I’m going to be making the same size 30m2 so would you please be able to tell me what quantities of materials I need. Thanks
Ali, loving these videos, can't wait to see how it ends up. I'm building a very similar structure at the moment. I wondered about the vapour barrier in the floor. You went for Celotex and then sealed that with the foil tape which would have give you a vapour barrier. I can't afford Celotex for my room so I've gone for some really thick polystyrene instead.. (something better than nothing etc). Would you add a layer of plastic over the top to create a vapour barrier? I can't find many sources of info on this
It is ridiculously expensive at the moment! Yeh definitely better than nothing. I would use one as if nothing else it will stop draughts coming in and general air leaks which cost a lot on the heating bills. You'll see in the next vid (part 10) how I use this on the roof: www.wickes.co.uk/Wickes-Green-Polythene-Vapour-Barrier---2-5-x-20m/p/153230. Of course, all the screws pierce it as they do for foil tape but overall it's worth doing I'd say.
Yeah it's crazy money. I'm going to opt for rockwool in the walls and only use celotex or similar in the roof. I'm hoping it will be enough. Thanks for the advice on the vapour barrier. Floor goes down next weekend. I can't wait to start work on the carpentry after what feels like weeks of digging and demolishing!
I think that sounds sensible. It'll be fine! I know the feeling Paddy, couldn't wait to be finished with demo/digging/blocks! But don't worry, you'll soon feel the same about the floor 😆
Hi Ali - love your work here....we've just started our log cabin in the forest....quick question, floor insulation going in this week.... You mentioned that foil-backed PIR needs 'several centimetres space above it' to properly reflect the heat back up. I've battened out my joists to make the insulation flush...worth re-doing this? It'll make sealing each joist bay more difficult.. Thanks!
Having watched the series about 10 times through now 😅 is this the part where you wouldn’t bother with the aluminium foil but use the polythene vapor barrier and wrap it under the plywood?
Some one said to me burr ooo no insects love PIR board and the bottom of the base should be sealed. I haven’t done this, I’ve done the same as you. Have you heard this re insects and if so did you take it into consideration?
This is excellent. Could I ask how you knew the ground under the blocks wouldn't sink under the weight? (what constitutes good ground for laying down the hardcore). We have quite clay like soil. Thanks for the tutorial, really clear
Blind hope mostly 😉 I just got down to ground that felt undisturbed and really firm. Clay has it's issues but it's not going to collapse under your blocks. Go deeper, pour concrete first if you are worried though
Brilliant video Ali, i am starting to build a garden room next week and this has been very helpful, thank you. Roughly how long did it take you from frame assembly through to finished subfloor? I am hoping for about 4/5 days work (mostly on my own) but i have a terrible track record of underestimating how long things actually take haha!
Everyone underestimates time, effort and cost of construction so you're not alone. This whole project, I didn't really know what I was doing, everything was new to me and there weren't great videos about to show how it's done so it took me a long time. I think the floor was around a week but I reckon now I could do it in a couple of days if I really went at it. The hammering in of the square twist nails is rather time consuming though.
Hi Ali, Just a quickie..... Do you have any "bounce" in your floor? I'm thinking of building a snooker room 8m x 5m. A 12' x 6' snooker table can weigh anything from 1200kgs to 1800kgs spread over 8 legs and I'm wondering if the pier foundations would be OK? Great series by the way really informative.
Just finished my own floor after following this superb 'step-by-step' video. The series you are creating is brilliant. I have a question now that my floor is complete...I was thinking of sealing the 2mm expansion gaps between the floor sheets with silicone - is there any reason you didn't do that? My thinking being it's just that little bit of extra protection against thermal bridging. Then I guess I would do the same for the walls and floor.
Nice one. Umm I can't see that helping with thermal bridging and I've never seen it used but I also can't see it hurting unless the boards expand and push the silicone upwards disturbing your flooring. Speaking of laminate flooring, you'll likely have a underlay which will act to stop thermal bridging anyway, if you're going that way.
I have use tgv ply for the floor and my carpentar friend advised me to use plenty of the foamy PU wood glue to seal the joins against rain. Although i am wondering if this will still allow expansion of the wood.
Great series of videos thanks! I am in the planning stages of a similar but smaller project. I need planning due to being in a national park, so hopefully no 2.5m height limit. What do you think of using a floating floor with the PIR on top of the subframe rather than between the joists to save the trouble of cutting it?
Is there any realistic concern of elements or animals messing up foam board insulation? It crossed my mind to put some treated 1/2in ply underneath the insulation, but I'm not sure if that's overkill. I want to get the floor right, because I'll have no crawl space to make changes once I build on it.
Hi. Thanks for these videos. Great source of information. I have a couple of questions if I may. On the video of the span stats, you said about when choosing the depth of your timber, this would effect the thickness of your flooring on top. I don't think you mentioned it again. ? I was hoping to go with the first one on the chart for the floor. 38mm by 97mm at 600mm centres which means I have to set my blocks at no more than 1.3m apart. I'm fine with that as blocks are virtually free lol. Will I be OK with 18mm thick osb or ply on top? I was thinking of rubber strips on the joists to help sound proof and also get to the magic 100mm for my PIR insulation. Also, can the walls be erected straight onto the frame and not the osb ? If why not. Many thanks and thanks for your time...
Just found this series, really helpful as it's almost exactly the same as what I'm currently building. One thing that's bothering me though is whether or not a ply floor will stand up to the rain while I'm building it? I think my ply is the same as yours, but I've already noticed a bit that seems to be de-laminating on the edge and it's been under a tarp since I got it a few weeks ago! I'm also concerned about standing the walls on the ply floor as that would make it impossible to replace in future. Any thoughts? Is it worth bringing it inside the walls perhaps (that would involve fitting a load of noggins for it to rest on)?
Ideally, I wonder if you were building the floor again would you put on battens of some sort for the PIR to sit down on a bit beyond the small battens put in place? Maybe they will do the job, but I'd like I think if i was doing it to see them sit down flush and tape from the underneath as well purely for the sake of overkill. But absolutely well done on ply over OSB. The fact that builders use OSB in areas of potential damp ingress boggles the mind.
Good question! I was wondering when someone would ask me that. Quite a lot of time is the answer and there's still a way to go with electrics and plumbing etc. However, I've been working out everything as I go along which shouldn't be the case for you with these videos! I reckon that 3 months working some evenings and weekends is doable to get a reasonably water-tight structure but I'd try to get the foundations done in April/May so you have those 3 months for the floor, walls and roof.
I’m currently replacing a rotten floor on an insulated out building in manitoba where winters can be as cold as minus 40! Planning to replace insulation with styrofoam. Is an inside vapour barrier necessary?
