Arg :( Extractor Outlet hole not central---- HELP PLEASE

[adrian_uk17]

Dear all,

I am about to install a new chimney style hood and after removing the old integrated hood have realised that the existing hole is not central

I have two options:

1. Try and get a slight dog-leg on the flexi pipe by digging away some of the intenal wall and plasteing over the other side

2. Drill a new hole..... and simply plasterboard over exiting hole?

3. Fill in existing hole and re-drill centrally

Any help greatly appreciated, does anyone know why the builders of the house would not drill the hole central to the hob??? Are they idiots or is there a good reason for this?

 

[r896neo]

Where is the hole, i assumed it was through an outside wall but your idea to ''simply plasterboard over it'' then makes it sound like it's in a ceiling? A photo would help.

 

[adrian_uk17]

Sorry no its through an outside wall.

When i say plasterboard over it I was thinking somehow to cut a hole at 45 degrees into the existing hole and then just block up the hole between the new 45 degree cut and the existing internal wall..... does that make sense

 

[Blagard]

If you are thinking about hacking it about and plaster patching I would be inclined to simply knock out one side of the hole to get the duct through when the hood and outlet is all squared up, and then make good.

Externally this may mean cutting out a brick or two and replacing to get a tidy finish. That's assuming you have brickwork external walls if course.

You didn't say by how much the original hole is out of position from what you now need, but I assume it must be close if you can almost get through it!

 

[adrian_uk17]

Hi thanks for the replies so far, If i were to cut a new hole in the correct place the holes would only overlap by say 20mm on a 100mm size hole

 

[r896neo]

As blagard says, your best option will probably be to forget the existing hole, create your new hole as if it wasn't there and put your sleeve/pipe in place.

Then replace the bricks affected by the old hole and make good around your new sleeve on the inside by building back in some bits of block or brick. Then cover the repair on the inside with expanded metal and replaster.

Obviously on the outside you will have to be very careful and perhaps a little clever to make sure you don't break or damage any of the bricks you take out as you will need them to cover the old hole.

Your best bet will likely be to actually only cut your hole on the inside and tooth out and remove the bricks you would be cutting through to replace in the old hole.
hmmm that is more comlicated to write than i thought.

 

[adrian_uk17]

OK i think i know what i need to do. Just out of interest i assume that i am not going to affect the strength of the house by cutting effectively almost a 200 x 100 oval out of both the internal and external walls?

 

[Blagard]

I assume that i am not going to affect the strength of the house by cutting effectively almost a 200 x 100 oval out of both the internal and external walls?

No, that is no problem at all - But as always when cutting holes in walls we should point out that your extension of the hole should not take it into any lintel bearing area.

You have me intrigued about what you are now thinking! I am guessing core drilling next to the old hole but then what?

If you had a photo of the existing hole from the outside you may benefit from the experience of others who know how to deal with the small adjustment you seem to need. Specifically with respect to the relationship of the current hole to the bricks.

 

[adrian_uk17]

Hi thank you all for your comments so far!! Very helpful.

I just took a look outside and where the existing vent exits it is on a set of bricks which lay vertically instead of horizontal, so i guess with the old hole i will just have to remove the surrounding previously cut bricks and replace with new ones. How many layers deep are the bricks usually? 1 or 2?

Also does anyone know what core holesaw i should get, i read on another forum that i can get a diamon core from amazon and attach to normal drill and use very slow RPM?

If so which one should i get? I assume 110mm would be the right size so i can use a standard drain pipe slid down through both holes?

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias=diy&field-keywords=silverline+core&x=0&y=0

 

[r896neo]

Firstly your mention of a soldier course of vertical bricks make it sound like it's near an opening? are there any nearby?

Secondly you really shouldn't use a core drill, especially not one that size on a drill with no clutch. If it jams it could easily break your wrist. Anyway seeing as though you need to salvage the bricks save your self the money on buying a cutter and just remove the necessary bricks and then cut and replace.

Mark the 4 inch hole where you want it and then any brick inside of your line or that your line touches you remove. Then stitch drill out the hole on the inner leaf and insert your sleeve. Then simply rebuild around the sleeve cutting the bricks to suit. This is what i badly tried to explain earlier.

 

[adrian_uk17]

Hi, i agree with you but.... i also have to buy a long masonry drill and thought with the core i could kill two birds with one stone.

The vertical soldier bricks are just a feature of the outside brickwork and extends around the whole perimeter of the house.

I will have a think about how to achieve you solution, but sounds relatively simple.

Any idea what i should use to plug up the old hole? Concrete fill the old tubes waste pipe and obviously use the bricks i remove from the new hole to plug the old on the outside?

 

[r896neo]

no don't fill the tube, remove it and rebuild with bricks or blocks or it will crack when plastered, as i mentioned earlier use a little bit of expanded metal mesh over the repaired area on the inside prior to plastering.

Really stitch drilling is very easy and gets a good result on blockwork, but is a problem sometimes on bricks but seeing as you need to remove the bricks then it will work well.

Surely you can pick up a masonary bit for a fraction of the price of a core and arbour etc.