Viewing 40 posts - 1 through 40 (of 76 total)
  • I need to cut a hole in my wall
  • molgrips
    Full Member

    Finally going to install a cat flap in the wall. What do I need to know? I’m a bit paranoid about damaging the house.

    The channel for the flap is essentially rectangular. Is this going to make the brickwork weaker? I can’t make it fully round (unless I then mortar the thing in place) because it’ll end up being larger than the flap surround. How significant is it if the hole’s not round?

    The other potential issue is that the outside socket is just above where I want the hole. Will the hole for that cable then weaken the wall if I go underneath it?

    I was thinking of using my 21mm or so masonry drill bit, going around the edge of the hole making small holes and then chopping it out with a chisel. The inside wall is just thermolite so that can be done with a hand saw.

    nickc
    Full Member

    Aren’t cat flaps cut into doors traditionally? Sounds a bunch easier than through a wall?

    wwaswas
    Full Member

    Chain drilling+bolster or an angle grinder – latter is going to be very messy.

    A bricks width missing from the wall isn’t going to be missing – your windows take out a lot more 😉 Try and make sure the hole has two half bricks on top so they’re supported by weight on the ends still in the wall.

    Also what sort of insulation is it? Might need careful cutting too to avoid too much damage. And make sure you don’t breach the damp proof course.

    the-muffin-man
    Full Member

    100% your cat won’t use it if you do go to all that trouble!

    It’ll be a cat tunnel not a flap – to your cat there will be all kinds of scary shit lurking inside! 🤣

    scotroutes
    Full Member

    Couldn’t you put it in a window and just use a ramp?

    nickc
    Full Member

    anyway, are cat flaps the new Mercedes? will there be pictures? (please let there be pictures)

    How much time do I have to get the popcorn before you start?

    molgrips
    Full Member

    Aren’t cat flaps cut into doors traditionally? Sounds a bunch easier than through a wall?

    Yes, but the door is a double glazed unit, and ordering another one of those is going to a) cost loads and b) take several weeks to fit and we need this so we can leave our cat at home for our holiday and we forgot to organise it in good time. Plus it means we can still keep the kitchen warm with the heavy curtain in the winter.

    Couldn’t you put it in a window and just use a ramp?

    Oof don’t, we’ve been through every possible combination a thousand times!

    100% your cat won’t use it if you do go to all that trouble!

    And you!


    @wwaswas
    ah yes. I was thinking of borrowing one of those hand held drill/chopper things like a mini pneumatic drill, but I do already have an angle grinder with an appropriate disc. That might save 60% of the chopping work.

    A bricks width missing from the wall isn’t going to be missing – your windows take out a lot more

    They have a lintel though! Fairly sure I don’t have cavity wall insulation and the DPC is safe. Good tips though thanks.

    avdave2
    Full Member

    21mm masonry drill applied to the cat should have the problem solved in seconds. I give you that it’s going to be a bit messy but hardly worse than than all the dust drilling through the wall will create.

    molgrips
    Full Member

    anyway, are cat flaps the new Mercedes? will there be pictures?

    It’ll either go ok or my house will collapse, so you’ll see it on the news.

    hardly worse than than all the dust drilling through the wall will create.

    House is that dusty already you won’t notice.

    tthew
    Full Member

    Fairly sure I don’t have cavity wall insulation

    Only fairly sure? – some of it is made of little loose polystyrene balls you know…

    mrmonkfinger
    Free Member

    Dig through the floor, under the wall, and make it a proper tunnel.

    Your cat can wear baggy trousers to disguise the disposal of dirt across the lawn.

    garage-dweller
    Full Member

    but I do already have an angle grinder with an appropriate disc. That might save 60% of the chopping work.

    They create an unbelievable amount of dust that gets everywhere. Alright if you’re cutting in an empty shell of a house not so much if you’ve got anything in the house / room. I put an angle grinder through a single skin brick conservatory many years ago for a dog flap. It was horrendous.

    You’ll spend longer clearing up than knocking out with a bolster.

    carlos
    Free Member

    I was thinking of borrowing one of those hand held drill/chopper things like a mini pneumatic drill

    If you have the option to borrow a core drill with a clutch and a 102mm bit, defo 100% do. So much easier, hardly any mess, cut through both inner and outer brick/block work at the same time and leaves a neat finish to both brick/block faces

    You could prob hire all the kit for a day for not much more than £35

    stumpy01
    Full Member

    molgrips

    Yes, but the door is a double glazed unit, and ordering another one of those is going to a) cost loads and b) take several weeks to fit and we need this so we can leave our cat at home for our holiday and we forgot to organise it in good time.

    Probably too late, but you can probably just get a new door skin, rather than a completely new door. That’s assuming it’s uPVC.
    It’s what we did when we had our windows and doors done; got the door skin replaced with a new one with a plain lower half.
    It was then dead easy to cut a hole in and fit the cat flap.

    Much cheaper than a while new door

    the-muffin-man
    Full Member

    Is there a shed you can put a flap in and make it comfy for the cat?

    You’ve just as much chance of teaching it to go into the shed as teaching it to wriggle through the tunnel of dooooooom!

    👹👹🙀🙀

    tjagain
    Full Member

    Most fun way is to use a petrol driven cut off saw thingy. I cut a doorway using one.

    mrmonkfinger
    Free Member

    SDS drill, big masonry bit, chain drill it. Only got one brick thickness to go through.

    Switch to the SDS chisel bit to knock out the bits between the chain drilling.

    JoeBones
    Free Member

    Make sure you protect yourself from silica dust!

    the-muffin-man
    Full Member

    Do a diamond pattern with a vent pipe drill bit? Think Hatton Garden robbery…

    https://www.screwfix.com/p/erbauer-diamond-core-drill-bit-127mm/1313v

    molgrips
    Full Member

    They create an unbelievable amount of dust that gets everywhere. Alright if you’re cutting in an empty shell of a house not so much if you’ve got anything in the house / room. I put an angle grinder through a single skin brick conservatory many years ago for a dog flap. It was horrendous.

    Hmm yes.. but, I can do the exterior bricks before I do the inside, and the interior can be done with a hand saw.

    singletrackmind
    Full Member

    Hire a 9in grinder
    Buy a 9in diamond blade
    Soak bricks 3 or 4 times around area.
    Sharpie marker square on wall.
    Have at it with grinder
    Amaze youself at your grinding prowess and the blades ability to slice through bricks like lurpack from the fridge.
    Drill through each coner of the thermal blocks then either sds stitch or bolster the square out.
    Fit catflap and render 5.1 mix 3parts soft, 2 parts sharp, 1 part cement around hole.

    squirrelking
    Free Member

    Probably too late, but you can probably just get a new door skin, rather than a completely new door. That’s assuming it’s uPVC.
    It’s what we did when we had our windows and doors done; got the door skin replaced with a new one with a plain lower half.
    It was then dead easy to cut a hole in and fit the cat flap.

    Much cheaper than a while new door

    Even better, can you not just replace the lower glazed panel with a UPVC filler panel?

    Again, that would be my solution and would mean you wouldn’t need a heavy curtain top cover a cold door 😉

    Failing that just forget about it and hide the cat in TJ’s trailer when he visits.

    (but yes, start from the outside and work in, if you have a sabre saw you can cut the block with that and an appropriate blade)

    molgrips
    Full Member

    Its double french doors, both sides are all glass, one piece.

    duncancallum
    Full Member

    Is it one off the pet porte micro chip ones?

    I think ours was just done with a drill and bolster but we had no kitchen in at the time so it wasn’t really a job that needed to be neat.

    retrorick
    Full Member

    I chain drilled a cat flap hole in a cavity wall. I was able to position the hole under a full brick which was supported either side by other bricks. Not the cleanest of holes be once the plastic external frame of the cat flap was installed it looks ok.
    Cat likes it.

    peekay
    Full Member

    If it is needs to be in quickly, and only temporality, open a window fully (or even remove the glazed bit), cut a piece of ply to fit, then put the cat flap in that. Secure the ply in to the opening using whatever modesty blocks/screws work.

    We have done this on a semi-permanent basis with a sash window. The wood is painted to match the window frames, and we have fixed the sash closed around the ply.

    molgrips
    Full Member

    Is it one off the pet porte micro chip ones?

    Cat Mate but chipped yes.

    matt_outandabout
    Full Member

    Just open the door when moggy want’s in or out?

    molgrips
    Full Member

    Just open the door when moggy want’s in or out?

    Hmm I never thought of that!

    mrmonkfinger
    Free Member

    Have you done it yet? It’s a two hour job, tops.

    You already got the kit to chain drill and chisel, and a hand saw, so I understand.

    molgrips
    Full Member

    Weekend. Someone’s offered to lend me an SDS drill and chisel bits, which is what the chap on the YouTube vid I watched was using.

    I’m going to have to move this outside plug as well.

    timba
    Free Member

    Google self corbelling brickwork. Chop a whole brick out as the Cat Mate box illustration shows. Hammer and bolster chisel will do and then complete the shape in the course(s) below
    Cat Mate make an extension tunnel, but I made something similar in wood (£13 for a bit of plastic was a bit rich). The wooden tunnel has the advantage that you can fill any gap between a whole brick width and the cat flap width. It also gives you something to screw into easily
    Two things to watch:
    polystyrene insulation (drill a 13mm hole in the mortar first to check)
    cable chase for the socket on the inside wall

    molgrips
    Full Member

    Well, yeah, I need 5 of those plastic extension sections, that’s fifty quid. So yeah it probably is worth making my own. Just need something that’ll be unaffected by water; since the door goes on the inside the tunnel is exposed.

    TiRed
    Full Member

    Across the road are renovating a shell of a 50’s house and expanding it x2. They’ve basically rebuilt a bigger house retaining two walls. they cut the holes for new windows in the front wall with the only tool (apart from a pneumatic hammer) they seem to own, a disc cutter. My god the mess, it rained dust everywhere. Without water to damp down the mess.

    Fit it in a door or don’t bother.

    jamiemcf
    Full Member

    You need a hilti DD350 and a 250mm diameter core bit.

    That’ll sort ya out.

    I’ve drilled 12m deep 76mm diameter holes through bridges with them. Can’t go wrong. Go big or go home.

    retrorick
    Full Member

    I didn’t bother with the tunnel extensions. I tidied up the brick with some mortar and sealed off the cavity.

    zomg
    Free Member

    I replaced the bottom panel (unglazed unlike the top half of the door, but the principle still holds) in the back door with a flat insulated door panel of the correct thickness. I think I had to cut it to size to fit my door, which was a task of similar difficulty to cutting the hole in it for the cat flap. It was probably a 20 minute job after sourcing the panel. I’d have put a glazed panel in the attic just as easily as I put the original door panel, ready to refit post-cat.

    zomg
    Free Member

    I see this wouldn’t work for you though. Have you considered having an indoor cat?

    DrP
    Full Member

    I just installed a cat flap on Tuesday…but it was in a UPVC door, which my jigsaw went through like a knife through butter!
    (Makes me realise, forget thieves trying to break a lock… an 8mm drill and a sharp jigsaw, and just cut out a HUMAN flap!!

    Anyway… good luck with the brickwork…. COre drill and SDS Chisel attachment w=should square out that circle!

    DrP

    irc
    Full Member

    Shed is the answer. Or in our case, summerhouse. Catflap in door. Cat sleeps there every night all year. Only allowed in the gouse when we are in.

    He has an electric blanket in his bed for the colder months.

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