My sod has been in 4 years and has looked great. Now on the southeast side of the house near my cedar deck it is dying. It is slightly sloped there. Neighbors tell me that is common from the runoff of decks. Is that true? Will it come back with a lot of water?

Lots of things could be causing it. A lot of clay or gravel in that area would be my first guess.

You say the area dying is slightly sloped. Do you mean sloped so that it's lower than the rest of the area... or higher? If higher - and especially if it gets a lot of sun, then it may not be getting enough water.

As for the cedar deck: I don't buy it. I've never heard it before and googled it a variety of ways and am just not finding anyone relating runoff from a cedar deck to lawn problems.

Anyway, watering is certainly the first thing to do to try to bring it back. Beyond that, you could call a couple local lawn care company for a "free estimate" and ask them what the problem is and what their recommended solution is - then tackle it on your own.

HI,
I agree with the cedar deck not being the problem. I cannot back that up with statistics, cause I can't find any on it either!
I do know there are homes around an 18 mile long lake in our local area, been there for years and years, many with cedar decks, outside stairs, etc, and it hasn't been a problem with grass dying.
I would check the ground "wetness" by digging a small hole, see if the ground is wet underneath the dying grass, maybe 3 inches down. If it's dry, then I agree with watering it.
The only grass that dies out is that which is under Cedar Trees, live, with all the needles and "fall-off" covering the ground. If you have an Agricultural or Farm Agent in your local area, take a sample of the dirt from that area to be analyzed. You might need more of a specific type of nutrients in the soil.

If grass has been OK for 4 years... is it because the decking is new?

My garden is fine around by the decking.

Is the dying grassed area, now, in a lot of shade... could be moss killing the grass. Is the grass yellowing, brown?

Look at http://www.turffit.co.uk/lawndiseases.html may give you a clue