Living Room : Filling in a Vent Hole

[dt00dmb]

Hi there,

I'm looking for some building advice. In the living room of my 1978 end of terrace on the end wall I have a vent measuring 24cm square. I believe it would have been there when the house had a back boiler installed originally. The house has cavity walls and I had cavity wall insulation installed when I first moved in 2 1/2 years ago, but I think the living room doesn't retain its heat because of this vent.
1. Is it ok to fill in this hole, considering there is no back boiler ?
2. How would I best go about filling it in?

Many Thanks View media item 89657 View media item 89658

 

[theprinceofdarkness]

I would knock out the outside grill and rebrick. If this is too much trouble, jam in a piece of hardboard about 1" on the inside of it, and render the grill outside. When its gone off, remove hardboard and render the inside of the grill. This is to provide a watertight seal to the grill.
Stuff the cavity with your favourite insulation material (glass fibre/ foam etc.). Brick or otherwise block up the hole on the inside skin and finally plaster over.
Frank

 

[dt00dmb]

Thanks for the reply Frank

I'm not sure about doing the knocking out of the outside brick grill and re-bricking myself ! Although I would like to do this as it is would seem to be the 'proper' way of finishing it. Do I literally just need to chisel out around the mortar, release the grill brick and then brick and mortar in its place? Being a novice, is this safe to do so ? I.e. I'm not going to weaken the rest of the wall taking the grill brick out ? I guess rendering it using the hardboard idea might be just as good a solution. Out of curiosity, if I didn't want to try it myself, and were I to ask a builder to do such a job, how much would you expect them to charge to do as you suggested in your reply?

Thanks for the help !

 

[xr4x4]

I'm guessing this doesn't vent the cavity?

 

[GoodDIYjob]

another cheap and easy solution is just to cut some insulation board to fit the aperture ( say using Kingspan or celotex).

If you want to you could adhesive in or silicon in around the internal perimeter to completely seal. You can then refit the internal grill with no redecoration. Of course that is not as neat as re bricking and re plastering but quick and effective.

I have done this for a similar vent in the kitchen which is behind the freestanding fridge. It's purpose must predate the current kitchen fit...

GoodDIYjob

 

[dt00dmb]

Thanks for the replies. It is the only vent in the house, on the end wall of the terrace. I don't know about it 'venting the cavity' I guess it does but there are no other vents around the house. I like the idea of the insulation board to fit the aperture, but I wonder then if the external vent could get debris in it and damage the insulation. I think I want to fill it in the way that Frank described in the opening reply. Can anyone help with whether removing the external grill brick will cause problems with the strength of the wall external wall ? Will it need supporting when the grill brick is removed? Can anyone give an indication of how difficult a job this is, would it just be better to render it on the outside as Frank described with the hardboard backing and then render on the inside of the grill in the cavity, and then block up the internal wall ? Thanks for the guidance.

 

[theprinceofdarkness]

Knocking out the vent will not weaken the wall unless the wall is in a terrible state.
Venting cavities is old fashioned because you get a gale blowing up them and it reduces the house to a single skin construction. Possibley the best value for money insulation is to stuff the open cavity top with glass fibre when you insulate the loft. This reduces the airflow to a trickle and your heat loss to a minimum.
Frank

 

[Nige F]

Probably the easiest for a DIY'er is a tube of clear silicone and carefully fill each hole in the brick from the outside , don't smear it all over just fill the holes neatly

 

[geraldthehamster]

Sounds like an opportunity for the OP to be introduced to the delights of squirty foam

Cheers
Richard

 

[Tipper]

If you still have a gas fire or other gas burning appliance in the room the air vent is essential to keep you alive!

Best to get advice from a 'Gas Safe' Registerd Technician (used to be called CORGI).

 

[Grenage]

Thanks for the reply Frank

I'm not sure about doing the knocking out of the outside brick grill and re-bricking myself ! Although I would like to do this as it is would seem to be the 'proper' way of finishing it. Do I literally just need to chisel out around the mortar, release the grill brick and then brick and mortar in its place? Being a novice, is this safe to do so ? I.e. I'm not going to weaken the rest of the wall taking the grill brick out ? I guess rendering it using the hardboard idea might be just as good a solution. Out of curiosity, if I didn't want to try it myself, and were I to ask a builder to do such a job, how much would you expect them to charge to do as you suggested in your reply?

Thanks for the help !

Having done this myself, with no bricklaying/mortaring experience - don't be daunted. Just take your time, and put some masking tape around the surrounding bricks, so you don't get mortar all over.

 

[geraldthehamster]

A quick way to prevent draughts blowing through it would be to fit a hit-and-miss vent on the inside. This would enable you to open it in a hot summer.

Cheers
Richard

 

[dominoman]

As Tipper said!

Do you have a gas fire or an older-style boiler in the house? If so, blocking this up could be a very bad move.