How to ensure window ventilation in bathroom renovation?

[Ben2065]

Hi everyone,

I am slowly restoring my heritage home (built aprox 1890's) I am currently trying to divide my original double hung window (no sash cord/pulley etc ever installed but slides very well). I need to divide the rooms along the blue line to allow a toilet room with small hand basin on the right (hot water service to be relocated) and a separate room on the left which won't be used for shower or as a wet room. I do not wish to interfere with the sewer plumbing for the toilet and therefore need to divide the window. After countless hours pondering what to do I have come up with a few options.

Option 1

Leave upper and lower window panes in their closed position and install window mounted exhaust fans either side in the upper window pane. I would install a timber fake mullion down the midline with foam seal against the window to allow the stud to marry up to this. I am concerned the noise this would cause on a daily basis.

Option 2

Leave the upper window in the fully closed up position and raise the lower window enough to install an opening floor vent (similar to this https://www.bunnings.com.au/accord-10-x-30cm-antique-brass-marquis-floor-register_p0810309 ) mounted in marine ply to seal the opening around the vent. This way I can open the vent to allow air flow and can close the vent to prevent airflow if cold/wet weather (this window is rarely exposed to direct rain or heavy weather) I am not familiar with these vents and if their closed position provides adequate air seal. Obviously it would be possible to attach insect screen material on the outside of this vent to avoid insects entering.

Option 3

Install an centre mullion and 2 casement windows which open into each room due to bars outside the window preventing outward opening. Whilst more ideal I can see this being a far more complex and labour intensive process

Option 4

Retrofit the window with a centre mullion and custom make double hung windows both sides with salvaged old timber windows. I am confident this would look nice however would likely be an extremely challenging and demanding process

I have considered retrofitting louvre glass windows either side however when this was quoted it is cost prohibitive (aprox $1300 supply only)

I would be doing the work myself and am confident with the timberwork and have fully restored the all the old timber double hung windows in my place. The image attached is an older image in my renos and shows the original arrangement of the window with the upper pane lowered to its resting position with insect screen material stapled in position.

I look forward to your suggestions/thoughts   

[Jason]

Hi @Ben2065,

Apologies for the slow reply. It's been a busy Easter for the team as they try to assist as many community members as possible. I'm sure @EricL will try to get back to you later today.

In the meantime, let me also tag experienced renovators such as @homeinmelbourne, @redbournreno and @Renowayoflife to see if they could share their thoughts on how to tackle your challenge.

Jason

[EricL]

Hello @Ben2065 

My apologies for the late reply. Have you considered installing a wall or ceiling ventilation system instead? This would save you from having to cut glass and have exposed wiring on the window. Modern wall fans are designed to go through standard timber frame and double brick walls. 

If you have space in your ceiling, installing a ceiling exhaust fan would be straight forward as all you need to do is to do a cut out and slip the exhaust fan into place. The plus side of this is that you can install a 3-in-1 fan such as the Click 3-In-1 Bathroom Heat Lamp.

In regards to the windows status, I'm putting my vote in having it totally closed and a mullion placed in the center where the division will occur. Since you'll be having ventilation in the bathroom, I don't think it will be necessary to have any part of the window open.

Let me call on our experienced members @Dave-1 @TedBear, @homeinmelbourne and @JoeAzza for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[Dave-1]

Afternoon @Ben2065 

Nice reno work for sure! I think it would be a lot of fun restoring a hertiage home!

I was thinking along the lines of @EricL's suggestion even before I read his answer. I like the idea of the fixed window and "mullion" down the center (Yeah I had to look up the word )

Are you allowed to put a hole into the wall at all? If you are you could have an exhaust fan through it to the outside or through the ceiling upwards to the ceiling space.

I like your option 1 and was just thinking more about it and the style of your house. Could you have the bottom part of the window fixed, the mullion up the center but the top 1/5 be a angled outwards, hinged at the top type window (depends on teh security bars), much like what you would see in hallways of old houses above doors? That way the room could exhaust and it would still look within style?

Dave

[Ben2065]

Hi EricL,

Thank you for your comments and advice. I have since found out that the room on the left will require the window to be kept shut. Therefore I am considering whether it is all that necessary to have an exhaust fan in the toilet room at all? It will be a large room at 1.4m X 1.4m with a false ceiling at 2.4m high or keeping the cathedral tng ceiling which goes to about 3.7m high. As there is a toilet and handbasin only there is going to be a minimum of steam/humidity so maybe not all that necessary. I could have a ceiling mounted exhaust fan however would be very reluctant to cut through the tng timber ceiling to vent the fan so would only be exhausting air into an enclosed space closed by gyprock under the tng ceiling which is likely not ideal.

[Ben2065]

Thank you Jason for your support and assistance!

[Ben2065]

Hi Dave,

Thank you for your assistance and comments. It truly is a labour of love looking after and restoring a 120 year old home but very rewarding. After 10 years there is still a long list but gradually getting there. As mentioned above I have since found out I need to have the window sealed shut on the room on the left of the stud wall so seems much simpler to leave the window in its fully restored state painted and locked shut with a centre Mullion to bring the stud framing to. 

I am not keen on putting in a wall mounted exhaust fan as the exterior wall is double brick and I would rather not disturb the wall. I was planning to put in a false suspended gyprock ceiling at 2.4m (just about the window) instead of the using the catherdral tongue and groove timber ceiling which goes up to about 3.6/3.7m high from memory. If I put in a suspended ceiling I could mount a ceiling exhaust fan but it would only vent into the enclosed gyprock lined space above the toilet room and below the tng ceiling likely this is not advised. I think at 1.4mX1.4m with normal or very high ceilings I may be just as well not worrying about an exhaust fan and keeping it simple as there will be likely little humidity as there is no shower in the room.       

I did like the idea of having the upper window as an awning style window hinged from the top although it would sadly require some destruction to the window frame to achieve this. As the left side of the window needs to be fixed that would make the conversion even more complex so keeping it sealed shut seems the best approach. Also means the mullion timber is not as critical as I won't be exposed to the elements either so I'm guessing treated pine should be more than adequate.

Thank you for your advice and suggestions it is much appreciated!

Ben

[EricL]

Hi @Ben2065 

Please keep us updated with your progress, we look forward to seeing the rooms once they are complete.  

If you need further assistance, please let us know.

Eric

[MitchellMc]

Hi @Ben2065,

Having an exhaust in a small bathroom is always a nice idea. However, it's not necessary unless it's required by code. If this toilet door opens into an open-plan living area and a kitchen is within the open space, I am under the impression that an exhaust fan is necessary if two doors do not separate the toilet from the kitchen. It would be best to consult with a builder in regard to suitable solutions.

Please let me know if you have any questions.

Mitchell

[Ben2065]

Hi Mitchell,

Thank you for your advice and input. There will be no kitchen in any of these rooms at all. Toilet room door will open through the narrow stud wall to the right of the image which will be a living space. I am once again back to considering putting in inward opening casement windows to allow air circulation in the toilet room and have the other side casement window sealed shut. A bit more work but allows airflow and avoids the look of a window mounted exhaust fan. Hopefully I can source some second hand windows close to the size needed to save a little bit of time. I am assuming that it would be best to use 90mm studs the the room division stud wall down the centre of the window. Thanks for your help Mitchell

Cheers,

Ben