sewage smell seems to be blowing back into kitchen on windy days? how can i stop it

[mrpipps]

hi all,
keep having what seems to be blow back sewage smells into our kitchen on windy days?
weve got the kitchen sink and washing machine in kitchen that both drain into the soil pipe in the corner of the kitchen,and a small toilet downstairs with sink that also drain into the same sewage pipe,and an upstairs toilet and and shower that also drain into the same sewage pipe?
but the smells only come back in through the kitchen,possibly the waste pipes and hose that takes away the washing machine water?the smell does seem to come from the back of the washing machine?
i clean the sink and washing machine regular with all sort of cleaners for washing machines,and carbonate soda and white vinegar,etc.
but still on windyish days we get what appears to be blowback smells from kitchen area only from possibly the soilpipe ?
is their any sort of valves that allows water out and stops blowback smells?its embaressing when people come to our house.
the sewage pipe is boarded around with either ply or plaster board and decorated so a bot difficult to get at to have a look?
any ideas please get back to me,thanks john

 

[Hugh Jaleak]

Need to see what the pipework arrangements are under the sink etc, is the washing machine drain connected correctly? Possible on windy days the wind is pushing foul air back down the vent pipe and into the room through open pipework.