What solution do I need to cutout a window in a wall on first floor.

Question

I already asked a similar question, on here, got some good answer, i would like to know if instead of the dawnting task to install a square window with lintel or steel frame etc... Would fitting a circular window/ Porthole window, be suitable, easier and cheaper ?? I have seen an estate near us of council house that seem to have this kind of windows for bathrooms.

Our house is 1950-1960, made of concrete blocks, the room needs a window but a small one will do, I intent to match rendering after fitting.

Thank you in advance,

Answer 1

You could do a round window, but you would have to line it with a circle of brick to act as an archway.  

Answer 2

square seems easier. whole blocks can be removedby chiseling mortar joints & replaced with 1/2 blocks where needed.

round sounds like a nightmare.

Answer 3

a round window is harder to do than a square one. even if your house in renderd you still have to build a brick bullseye to form a strong round hole, also it will still have to have a lintel slightly higher than the opening. if the rest of your windows are square than you would'nt get planning for a round one.

Answer 4

A golden rule of building is that circular is more expensive than square.

You still need a lintol whatever shape window you have - usually you end up with a complete rc frame with the circular cut out for the kind of porthole you are talking about. Building inspectors tend not to accept brick arches and you will have difficulty producing calculations for them. Alternatively you could use steel, but again it has to be specially fabricated into rings.  Portholes don't normally open but are (even) more expensive if they do.

If it was me I would do the square one - its a breeze to do - needle up and stick conc lintols in each side - ideal if you are going to render. Working at high level could be a difficulty though. Have you thought about a roof light?  

If it is a bathroom I wouldn't bother with a window at all - just put in an extractor.

Answer 5

there is a new con saw you can hire-its called a cut and break concrete saw. it will cut up to 16" deep from one side. steel nail firmly a piece of plywood on the outside where the window will be. this saw will then allow you to cut from inside,stopping 1/2" from outside wall.after removing the inner leaf of blocks and cutting most of the way through the outer, go outside,remove ply and hammer through the outer leaf of blocks into the room. allow for your window sill and lintel in the height and cut out the appropriate cuts on the 2 top corners for the lintel to span block-work...it depends on window size but on a doorway say, you'd be about 6-8" past on each side..and secured in strong mortar. do not attempt this unless you have some experience!