It’s a common occurrence to run across a roof which has a chimney too wide across the back. Both brick chimneys and wood sided chimneys need crickets if water or debris is getting trapped behind them. Either way a chimney which is too wide almost always needs a cricket build behind it.
What is a chimney cricket? A chimney cricket is a structure build on the uphill side which has 2 valleys and a small ridge built in it to divert standing water and debris. Chimney crickets don’t allow water to pond on top of a chimney.
When a chimney cricket is properly built it will have ice and water shield behind it. At Pro Roofing NW, we prefer to use synthetic felt on top of the leak barrier.
It’s not necessary to install a ridge vent on the small ridge of the chimney cricket because it’s not on top of the roof. In some cases a rolled ridge vent might be a good option as an intake vent if the roof line needs more intake venting. That scenario is very rare however because proper venting can almost always be reached with soffit venting or eave venting.
After the structure of the chimney cricket has been build metal valleys should be used as flashing.
Then the new chimney cricket structure needs to be flashed into the chimney side wall or the siding.
Lastly the roofers will install the shingles and the cricket will divert water.
A price from $150-$500 is usually appropriate for this type of work to be done. There are lots of levels of difficulty so the price will fluctuate.