How to convince plumber that there is a gas leak

We had a leak going into our ceiling. Luckily, as a wood turner, I already own a moisture meter. This can test the moisture content of wood (but other similar density substances too) merely by pressing a button. That meter worked very well for my problem. Of course, if you do buy one, I don't expect you will find many other uses for it than catching an occasional leak, but it can still be cheaper to buy one than to pay someone to make a simple reading for you. Just store the meter after you are done with it with the battery removed.

It will take several weeks or even months for a ceiling to dry out. This depends on how enclosed the area is, and whether there is still water getting in. Readings made over time should be decreasing. If not, there is still a problem. The moisture content of even dry wood will be around 8%. Check other walls in your house, because this number will vary by where you live, and what time of year it is.

There are several styles of moisture meters. One relies on pins that must be inserted into the material, testing electrical conductivity between the points. As such, it will leave small holes. Better are the styles that do not leave a hole, but they are more expensive. Note that the cheaper models use a probe. This probe will have pins to stick in the wood.

By the way, while the ceiling is still damp, stains WILL continue to spread by capillary action. The water will continue to wick the stain further away. 2 months later is a long time for new stains to appear, however, old stains can bleed through new paint. You may wish to use a product like Kilz to seal in those stains. But wait until it is surely dry before you paint. This is where the meter will help you out.

If you are on a municipal system and have pressure that high, you quite likely already have a pressure reducing valve (PRV) installed near your water meter. The International Plumbing Code requires PRVs on any water supply over 80psi. If this is the case, your PRV may just need adjustment. As they age, the spring regulating the device's operation can soften. Or it could be faulty and need repair or replacement. If you do not have one, you need to have one installed.

If you are on your own well with a pressure tank, the pressure switch controlling pump off operation needs adjustment. Other types of systems should have similar arrangements to control pressure.

How to adjust a PRV. There is typically a bell shaped housing with an adjustment screw and lock nut on top. Loosen the lock nut and turn the adjuster counter clockwise a small amount. The adjustment can be rather sensitive. Operate the faucets and toilets in your house to allow the system to equalize to the new pressure setting. Take a new pressure reading. How much it changed will give you an idea how much more adjustment is needed. Typical water system pressures should be somewhere in the 40-60 psi range. Shoot for the high 50's.

If the PRV controls supply to a fire sprinkler system (it normally shouldn't), you will need to check with a fire supression professional to determine if and how much you can reduce the supply pressure.

If you do need a new PRV, check with your municipality, they sometimes offer rebates to help mitigate some of the cost.