Garden Room Workshop Extra | How To Stop Mice Under Your Floor!

[@AliDymock]

Just a short one today. Are there any preventative measures I didn't think of?

[@opumfrey7625]

I think using wire mesh to keep out mice would be very difficult for the reasons you mention. To keep them out you really need a complete seal as they can fit through a hole 6mm wide. I’ve seen specialist rodent mesh on Amazon (£30 for 50cm x 50cm) and that has 1.19mm holes and is clearly expensive. If using PIR board I don’t think it an issue, as you have found.

[@anthonymcintyre6254]

Cats are not a good idea for pest control, they may bring them in the house alive.

[@northeastcorals]

@@opumfrey7625 Yeh if you can poke a pencil through a gap/hole then mice can also get through so the effort/cost/time to make a building truly mouse proof is just unrealistic bearing in mind they can also chew through most materials apart from metals etc. If you did get an infestation poison in a proper locked bait box will set you back £20 ish plus re-fills depending on how bad the problem is!

[@Tom-Lahaye]

I can confirm that rock wool or glass fibre insulation make great nesting material, especially the non bound type you can buy on rolls, often with a paper casing around it. I just finished demolishing some ceilings from under the flat roof of my house, and had never experienced a shower of mouse and rat faeces like when I started to rip the insulation out. The insulation was done wrong anyway, the roll was tacked with a nail every foot or so, no taping and no vapour barrier installed. Result is that the underside of the plywood roof boards are damp and mouldy, but luckily not rotted yet, apart from a small older looking piece. On the insulation however I found small rotted pieces of chip board, so apparently this had been used as roof boards before, and the combination of the chip board, insulation and no vapour barrier had apparently disastrous effects in a very short time. But DIY people in the 1970s and 80s when this was done didn't have access to all the knowledge we have now with internet, so mistakes were very commonly made. There is a new roof membrane and warm roof insulation going up. On the garage connected with the house straw cement boards have been used and these are deteriorating, new boards will be laid on this part anyway, so any less than perfect boards on the house part will be replaced as well, some boards aren't rot but have sagged a bit between the joists and this promotes pooling of water on the roof.

[@boyblunder8889]

Rats taking up residence under my old summerhouse has been a big problem , I’ll need to deal with that on the new project that’s in planning now. Great stuff 👍

[@hitmon]

Great video. Love your use of Sketchup to clearly show what your saying. Would you consider making a quick tutorial on how you use it yourself and how you built your models for the garden room? i.e. NOT a total beginners guide. Thanks!

[@AliDymock]

It's a great idea. My plan is to keep focussed on the build part of the series with these little extra vids in between as I don't want to drag it on any longer, especially as the build is finished IRL but after that I will definitely see what I can do on the design side 👍

[@TrotterG]

Would the OSB underneath present any risk of trapping moisture and causing issues?

[@mohammadsiddiqui2169]

Good morning, what size timber you used for the floor. 150x50? Thank you

[@chrisfreestone5752]

Great vid, to the point and informative (and the answer I wanted!). Thanks for making.

[@captainbuggernut9565]

Apparently mice and rats don't like the thin foil that covers the insulation. They cut their mouths chewing on it. Or so one manufacturer claims. Personally I went with vented membrane, £34 for 50 metres and mesh which I already had for fencing. 6mm holes and £50 for 15 metres from Amazon. I put that over the membrane and stapled it round the floor. Stood on some cheap, green treated bearers which were £4 for 3.6 metres from Travis Perkins.

[@stevet9487]

Ali I jest wanted ask one more question, I have decided to concrete the base but wanted to put a damp proof membrane in and I have looked on the web and not found a reasonable answer. Do you know if it’s best to put the damp proof membrane concrete and Typ 1 or over the concrete. Thanks for being there.👍

[@AliDymock]

I don't quite get what the question is here but if you look at my thermal mass video you'll get a good idea of the possible build up of layers for a concrete base. The DPm should be between the sand blinding and the insulation/concrete but you can also put one on top of the concrete if you are having flooring just to be on the safe side. Hope that helps!

[@stevet9487]

👍

[@joeharman8394]

Just in the process of planning a garden office build and having the conundrum of concrete slab or concrete block foundations. Now leaning towards the former given this video even with the extra cost. May I ask what you would opt for if you was to build another garden office?

[@AliDymock]

It's a great question Joe. If we turn to house building both concrete slab and timber floors are used to this day so one doesn't necessarily have the upper hand over the other, they both have pros and cons. If the site is right for a concrete base I'd lean towards that, mostly for the height gain. I'm planning a second one and think I'll go with concrete as the site is flat which makes things easier.

[@craigwelsh]

For my log cabin foundation i stapled chicken wire (4 layers thick) to the perimeter double beams and hammered weed control spikes through it into the weed control to keep it in place. Gravel a few cm deep is in a channel around the building uo against the chicken wire so if anything is burrowing under i should know from that. I do have foxes, squirrels and mice in the garden and not spotted anything attempting anything yet thiugh the main floor has only been down a month. Incidentally i did find earwigs liked to burrow a little into the pir while i had it stacked in the garden awaiting cutting etc. They didnt get far in before dying though! I believe a lot of them hitched a ride to the UK from holland with my cabin.

[@lukedogwalker]

Maybe the earwigs preferred the darker, moister atmosphere between the closely stacked sheets. When laid out and open to the air in the floor, it won't be as attractive.

[@hyseb2]

Damn man, that ending is a helluva cliffhanger!

[@rdownmakeITbetter]

As I understand it mice and rodents are attracted to thermoplastic such as expanded polystyrene which they can actually digest. However, most insulation products these days are thermoset plastics (for obvious fire resistant properties) so do not appeal in the same way.

[@colinwhite6132]

I went for a chicken wire and thick gauge mesh. I stapled mesh (which I reclaimed from a municipal tennis court refurbishment) and then folded it flat for 2 ' out from the building. This was covered with gravel, to prevent foxes digging under.

[@AliDymock]

Sounds solid Colin! Should out-wit a fox, a least for a while!

[@congabriel5469]

I was always told rodents wouldn't like the rockwool, am I wrong? Has anyone had experience with that?

[@Jarul0706]

Good video 👍🏼, it's the reason I plan to put in a perimeter wall

[@AliDymock]

Good thinking!

[@benboy796]

Hi Ali, thanks for all the videos you've done I'm just a floor level now. I'm going to leave the underside exposed exactly how you have. From a few other videos I've seen, it's been suggested to allow a gap for both cats and foxes to get under to be a natural pest control measure. Makes sense to me. If your garden room is to be used on a regular basis foxes are unlikely to create a den under it 👍

[@AliDymock]

That makes sense 👍 It’s interesting the questions I get, everyone seems worried about something different.

[@rafters21]

Love the videos, thank you! Would you have any concern with using OSB to support the insulation given that it would be exposed to the elements and supporting the entire weight of the building?

[@AliDymock]

The underside of the floor should stay dry (once the roof is on especially) so no worries there. As for the weight, I think it would be fine but you could just cut around the blocks so the joists are sitting directly on the block piers (or whatever you use) rather than the OSB

[@MagicMarvin33]

I had squirrels and mice ruin my board insulation. Don't think they would eat it but if they can they dig into it. as long as its not exposed I think it should be fine. Most was fine but parts where it fell slightly or was pulled out by them they tunnelled into it.

[@LluisTheWoodWorker]

Nice info! I have a brown rat under my workshop, quite big about 40cm in length including the tail. I really don't know too much what to do I have tried poison but it hasn't even touched it. I can hear it chewing the insulation or joist... quite worried but i really don't know what to do! Thanks for the vid love them!

[@AliDymock]

40cm! That's a big rat, hopefully there's just one of him. Usually warfarin does the trick but maybe you could get a live catch cage thing and put some peanut butter or biscuits in there. Problem is you might catch a squirrel instead and you're not supposed to just let them go...

[@LluisTheWoodWorker]

@@AliDymock Yes I was thinking about that but I'm not too sure need to try various methods. I have done some research by putting a night camera and I have only seen the same rat over the course of a week, but there could be more now I need to get back into it.

[@Figure11_Home_and_Garden]

having just rid my chicken coop of rodents I offer this, your scent is probably all over the traps, this will stop them coming to them. Leave the traps in the rain for a week or so and wear disposable gloves when handling the traps and poison. put the traps close to where the rats are travelling. Tunnel traps are best. hope this helps.

[@LluisTheWoodWorker]

@@Figure11_Home_and_Garden Thanks so much will try! I have been desperate to try to get rid of it!

[@nomdeplume3755]

@@LluisTheWoodWorker sorry I know from bad personal experience that they don't live on their own. They can breed every 7 weeks as I remember, so you might have a couple of generations by now. I bought a rifle, shot a few (fun) trapped even more (the most work baiting and rebaiting) and finished them off with poison (easiest). Left that till last as I didn't want rotten bodies in cavities but it was the most effective. They liked the pasta bait from Screwfix or toolstation.

[@TheMartinlt1000]

awesome, thanks man. I think i’m going to go with the wire mesh around the perimeter. backed up with a tripwire and a series of guillotines. lasers maybe, solar powered lasers. 😂😂😂

[@AliDymock]

😂Good luck!

[@TheMartinlt1000]

if i can finish the framing the walls and get it watertight i’d be happy tbh. this bloody weather is a nightmare.

[@AliDymock]

Yeh, mud is not fun, I’m a fair weather builder me 😉

[@michaelrauch4017]

Hello Ali, Sorry for jumping onto this video with my question that isn't mice related! I followed your garden room videos, to help me create my own garden room, they have all been very helpful, so thank you for them..I have used tyvec house wrap on my room and decided to add a small storage room on the back of the garden room, and need to know if I can use the back wall of the garden room to double up as a side wall for my storage room, and if so, can I leave the house wrap on the garden room wall? or should I have the storage room with a wall of its own and then perhaps a gap between the two buildings? Any tips or suggestions greatly received, thanks look forward to your reply. Mike

[@AliDymock]

Hi Mike, totally fine to attach the two and leave the tyvek in place. It also acts as a vapour barrier for the storage room if you're heating that space. Only thing to watch out for is don't go into building regs territory as the building will count as one so if all together you're under 30m2 internal floorspace you're fine (assuming UK).

[@michaelrauch4017]

Thanks for replying Ali, what you've written makes sense, gives me the confidence to go ahead, the overall floor space will be under 30m2 so all good there. Thanks again Mike

[@lukedogwalker]

I'm a fan of a perimeter foundation, partly for load bearing, and partly for keeping the rats out. They like to burrow under supports, and I don't want them undermining a plinth! I may use plinths inside the perimeter, or just subdivide the area with extensions of the perimeter, which should ensure I get a very solid floor. Also, at one end of the building I get a lot of leaves and other material blowing in, and don't want ritting masses liling up underneath the floor. The perimeter should keep that out.

[@AliDymock]

Very good point about the leaves!

[@Benzknees]

Mice got below my house floor despite air bricks being the only entry point. It’s amazing what space they can squeeze through. Nevertheless they don’t appear to have ever chewed thru my electric cables (I hope!), which you’d think would be an obvious target.

[@northeastcorals]

If you can poke a pencil through a hole then a mouse can get through it.

[@ajc7166]

I left a piece of left over celotex out for a while and noticed that small insects were boring into it.

[@AliDymock]

That's interesting to know. I image that as long at they can't get in the sides, the foil will keep them out but maybe the tyvek idea would be a good one.

[@ajc7166]

@@AliDymock I guess so, seems likely as they had only bored through the exposed foam.

[@stevet9487]

Thanks, I am putting up my log cabin in about a week and a half, I still don’t know how to deal with the underneath of it, but thanks anyway.

[@AliDymock]

Best of luck with it Steve. Go for the perimeter wall if you're really concerned.

[@jb223]

great tips 👍

[@CreativeTechno]

Hi Ali, another great Video! They have really helped me a lot, love watching them. May i please ask which 3D Design Software you used?

[@AliDymock]

Glad you like them. These were made on SketchUp!

[@CreativeTechno]

@@AliDymock Many thanks Ali, i never realised SketchUp was so good, must give it a try :)

[@nguyenxuanson]

Hi, I am thinking about building my garden office myself. My concern is that: how can I avoid the damp damage the timber structure which are in contact with support blocks in your video?

[@teatimetraveller]

generally not a good idea to run vertical cladding down to ground level as its likely to get stained by rain splashing off the ground or the end grain absorbing moisture from the ground and rotting. generally good to run an horizontal board along ground level to butt the vertical boards onto. this can be replaced if it gets damaged, called a gravel board.

[@AliDymock]

You mean like a fence? I'd agree with that for timber cladding as the most sound way of building but for many the aesthetics suffer too much to do it...

[@teatimetraveller]

@@AliDymock well its not as ugly as stained cladding! its actual fairly common in joinery to butt square cuts up against some form of perpendicular trim.

[@nickwallette6201]

@@teatimetraveller If you have snow to contend with, it's common to have a whole foot of space between ground level and siding. There's a lot of exposed outer insulation (neighbor has some foam boards showing in the last few inches), cement block with tar, that sort of thing. Where snow _doesn't_ pile up, at least a couple inches to avoid splashes and wicking sounds pretty reasonable. I definitely would not run lumber and siding not rated for ground contact all the way to within an inch or two of the ground. (But what do I know?)

[@TheLoOPerMAN]

Whats the 3d software you are using called?

[@AliDymock]

SketchUp!

[@CharlieZenenour]

the best way to finish the underside of ground floor suspended timber fllor is to install cement fiber boards underneath, stack two layers staggered. That way it complies with fire safety regulations in the building code and fully envelopes the building from the weather. Of course you also have to use a vapour membrane and a weather protection membrane as well, just like in the walls.

[@stevet9487]

I wasn’t concerned until you made your new video thanks

[@AliDymock]

😂

[@rex182k4]

wheres the video about the Wasps? I live near a canal, so there are quite sizeable rats in the area. need to make sure I dont give them a home!

[@magill4046]

Good info as ever 👍

[@teacake4922]

Wasps in the soffit.....the stuff of nightmares.

[@georgerothwell]

Good video

[@_babyjesus]

Nice.

[@Pete.Ty1]

😊👍

[@LabRat6619]

Do your installation then put poison down before finishing your project.

[@TheDaztheraz]

Got rats in my old garden room, got underneath floor and into walls 🙈

[@postmodgent1499]

spray foam

[@oliverwallace3211]

WASPS!. And he's making us wait to find out.

[@AliDymock]

Not too long, promise!

[@CharlieZenenour]

rats don't like closely packed mineral wool, unles you buy a loose roll of mineral wool there's no way in hell a mice can nest in rockwool It's too rough and the tightly entangled, it hurts the rat and starts to peel it's skin off. If the rat dries to push it's way in all the rat will accomplish is loose it's tiny limbs and get deep lacerations. Educate yourself.

[@randommusings48]

Just realised the cat is playing with a mouse.. yikes!

[@AliDymock]

yeh I wasn't sure about it but I figured it's no worse than a nature doc so decided to include it. That was at the garden room actually when we brought him there for the day. At least he eats them rather than just leaving them around the house.

[@nickwallette6201]

@@AliDymock This video is rated N for Nature. The food chain wasn't _our_ idea. ;-)

[@jayseabie215]

Typical cat, playing with its food.

[@skyhigheagleer6]

All good info but cats killing local wildlife is not the answer.

[@AliDymock]

You're right. Getting a cat was meant in a tongue in cheek way, just if you have one mice might not be a worry so it felt worth mentioning. While I'm happy for him to catch mice in or near the house, I don't encourage him to catch birds etc

[@skyhigheagleer6]

@@AliDymock lol I've been meaning to do the chicken wire on our log cabin, might stick a camera underneath and see what's decided to inhabit the void since it's been built.

[@AliDymock]

@@skyhigheagleer6 I'd be interested to see. As you saw from the video I undoubtedly have at least one glis glis under our shed. It can have the winter there as I'll be demo-ing it at some point!

[@nickwallette6201]

Are you _sure_ it's not the answer? That is, afterall, what cats eat when they're not artificially fed from a can and a giant bag of processed flora and fauna. The natural world would generally rather us avoid imposing our subjective morality on it. It tends to flourish without our intervention, and any attempts to improve it only disturb the equilibrium.