I want to convert my laudry room into a dual room I would like to add a shower sink and toilet.. the hot water and water connections are there for the washer... I do I ty into the existing pluming to install the toilet? The house is on concrete slab and the main bathroom is about 20 feet from the laudry room .

You will have to break up the cement for most of the drainage. Tou may use the washer vent for your lavatory. Cut out the washer trap and standpipe and install a sanitary tee and stubout. The toilet will connect to the sewer main under the slab and the shower connect to the lavatory drain and be wet vented by it. The water you can pick up from the washer supplies. Good luck, Tom