Hallway smells of eggs?

[bilbodog]

Just noticed our hallway is smelling if eggs and having googled drains is the most likely cause as the downstairs loo has had a ‘drainy’ smell for a while.

@pigletjohn

We have the attached inspection cover not far from the house but cannot open it - the screw heads do not budge.

Anyone got any ideas how to open it?

Get a screwdriver that is a correct fit

Please close-up photo of the screw heads.

Oh,
I see now, they are ordinary slotted. The correct size will fill the slot and have no wobble

A set of screw bits and a T-handle socket will maximise your power. Used with two hands

I'll see if I can find a link.

Grease the threads on reassembly

Sorry for the delay

I recommend a T-handle tool because it enables maximum force, and by using two hands, does not apply sideways pressure causing the tool to twist and slip out.

An old, worn screwdriver, or an incorrect size, with probably not work and will damage the screws.

What is the approximate diameter of the screw heads?

Do you happen to already have a set of screwdriver bits (often supplied with a drill or in a kit) and is one big enough?

They often have a 1/4" square drive or a hex drive.

A car maintenance socket set will not usually be small enough, unless it includes some small accessories of the screw is unusually big

I am assuming that you will not want to spend much money on a set of tools you will hardly ever use, unless you take up washine-machind repair or something.

For info, a T-bar tool will look something like this

www.ebay.co.uk/itm/JIS-T-Handle-Screwdriver-Set-Japanese-Industrial-Standard-Screw/184022276167

Though the one in the link is not the one you want.

It illustrates how you can get a really good turning force.

Thanks @PigletJohn. Ill see if we have anything like this. Ive tried with a normal screwdriver but the screws dont budge at all.

Can you measure the screw-head please?

Here you go

Photos

So I think it's about 3/8"

Assuming you haven't got any screwdriver bits or a socket set already, I will have a look for a T handle solution.

Thanks

well this has been amazingly difficult

usually these things are sold in sets

such as this, which includes a T-bar plus numbers of screwdiver bits in various sizes £24 at Halfords or a cheap set off ebay

Looking for the individual parts, I managed to find a couple of T-handles in 1/4" an 3/8" sizes

good grief, the T-bar alone is £20 or £10 on ebay

And some individual bits

£11.70 on ebay or a 1/4" bit holder meaning you can use readily available screwdriver bits from Aldi or ebay

but they seem to work out around the same cost as buying a set.

If you want a set, the Halfords £24 kit is I think more useful for household repairs, on the bike, assembling beds and furniture. Screwfix have some cheap sets but they do not have the T handle which in your case I think is necessary. It enables you to turn tight screws and nuts even if your strength is poor. If you see a 3/8" set it is stronger than the 1/4" set.

but is it worth the money to you? Maybe I am worrying needlessly

if it means you find and clear the blockage, and it saves you a plumber callout, then yes.

Thanks @pigletjohn - i will let you know how we get on.

@pigletjohn we still havent managed to open the inspection chamber but have managed to get rid of the drain smell - we have a downstairs shower which we dont use and i read that the u-bend could be dry and letting smells up so i filled it up with water and voila! No more smells!

We will get a plumber or builder to look at the drain cover in future if we have them in for something.

Thanks for your help.