|Posted on Friday, September 03, 2004 - 02:17 am: ||
What is the correct procedure for replacing the flashing in a closed valley? I have six large valleys and two are very small.
The house is 75 years old and prior owners, of course, had some of the valleys tarred. I had one firm who supposedly does nothing but residential slate repair tell me the proper way to replace the valley flashing "only remove a few slate at a time starting at the bottom then replace the flashing in a diamond shape and replace the slate going up the valley". I thought I had read in the SRB all slate in the valley was numbered and removed. Flashing replaced and then put the slates back on the roof.
Is their a right way and a wrong way to do this repair?
This guy said I misread the SRB. I don't have the book to refer back to as I lent it to a friend who is supposed to buy his own SRB.
The gutters on the house need replaced as the old copper gutters were replaced with aluminum which were installed wrong. No end caps. Gutter ends sealed with tar against the slate roof. The old copper flashing that went up under the starter course was never replaced and is very ragged. Have had to repair brick work in several places due to water getting behind brick and freezing.
The house has only a few inches of slate that act as an overhang. Should I use copper or aluminum for the new gutters?
The guy from the firm told me copper should be used as it would have no seam in the flashing, he would remove the starter course of slates and the flashing would go up under the slates and then come down to form the gutter so it would all be one piece.
Any help on this would be appreciated.
|Posted on Friday, September 03, 2004 - 10:20 am: ||
We'll first let me say both (your roofer and Joe is right). If you have closed valley"s (which i've personnelly replaced hundreds of closed valleys) what your roofer is saying is closed valleys tend to be step flashed and yes you can take out some slates put the flashing in a step it back up. Although I prefer to remove the complete valley and step the valley flashing laying the slate back in as we go. When you read the slate roof bible it was for an open (metal shows) valley. Normally we do number our valley and side slates to make re-installation quicker but, as you state your slates are covered with tar we would number the slates for pattern purposes only and replace the tarred slates with new or recycled slates. Who wants to put good money into replacing valley metal and look at tarred slates, not me or my customers. Your slate roofer is correct in his method to replace the gutters also. It's really the only way it should be done. Sounds to me like you've found a good slate roofer, you take it from there. One more thing make sure all seams are soldered and pop rivitted. If possible fold and lock roof to gutter seam. good luck
|Posted on Friday, September 03, 2004 - 11:46 am: ||
I prefer to completly strip the valley back removing all debris and cleaning the deck so a new layer of 30 lb. felt can be laid down.I don't worry about numbering the slates since many are either broken or too tarred up for reuse.You'll need more slate ,either salvage or new to complete a closed valley replacement.
Have you given any thought to converting the closed valleys to open ones?
In this way you can eliminate the bad slates and still have enough for the re-install.
If it's in a Historic District then you might not be able to get a certificate of appropriateness for it,or you might not find the open valleys appealing either.
|Posted on Friday, September 03, 2004 - 01:09 pm: ||
We always remove the slates from both sides of the valley, starting at the top and working down, until the valley is competely exposed, old metal removed, wood deck swept, and new metal ready to install. We would never replace a valley by starting at the bottom or by removing some of the slates a little at a time.
Having replaced literally miles of valleys, we do it the most efficient and effective way. We usually number the slates, starting at the top, as shown in the Slate Roof Bible, by scratching with a nail because it saves a *lot* of time when putting the roof back together. We replace broken or tarred slates individually as we put the slates back on. This is easy to do when the slates are numbered because you only have to take the numbered faulty slate, lay it on the back of a good salvaged slate, use it as a pattern to mark the new slate, cut the new one and then nail it into place. It's quick.
Unlike Walter, however, we do not use underlayment beneath our valley metal of any kind. It makes no sense to me to have underlayment under the valleys and no where else on the roof (on old roofs, the underlayment has been shot for decades and the roof relies only on the slates and flashings to be waterproof). If water is getting through the valley, something is very wrong. If water is not penetrating the valley, what's the point of the underlayment? We use half-hard 20 ounce copper (or stainless), not soft copper, for our valleys, so we don't need a cushion under the copper.
On the other hand, we *always* replace a valley in a single day, no matter how long the valley is (the longest is typically 34 feet, which I have done myself, alone, in a day). If we had to leave it overnight, we would certainly install felt in the valley to weather it in. Some contractors typically spend two days replacing a single valley.
There are some arguments that felt under valleys prevents condensation under the valley metal in the attic. However, old tin valleys rarely have effective underlayment beneath them and they' don't have condensation problems. I should add that our valleys *never* leak. Having installed valley replacements for 25 years in this manner, not one has ever leaked or been a problem in any way. That's good enough proof for me that we're on the right track. This isn't to suggest that there aren't *other* ways to replace valleys that other contractors may prefer. I'm simply describing what we do, based on our experience and our desire to be fast, efficient and effective.
By the way, there is a closed valley replacement sequence of illustrations in SRB2 , page 271. It's rather rudimentary, but you get the idea.
|Posted on Friday, September 03, 2004 - 02:39 pm: ||
We number from the bottom up so when you are reinstalling them you start with #1 and work up. However we do remove from top to bottom (it's easier). We also like the fact of having an underlayment we use 30# felt. If the roof has a closed valley system we stay with that method because, we are into restoration. If it is an open valley then we reinstall it that way. Step flashing a closed valley is the best way. Even if the slate is broke we number it so we have it for a pattern for reinstallation. Numbering the slates when taking out makes for quicker reinstall of slate. We also like removing all the slate and as Joe states you can dry it in (if you have to) overnight. Spencer P.
|Posted on Friday, September 03, 2004 - 03:56 pm: ||
I always believe in using an underlayment for a couple of reasons.
First I treat a new valley install whether it be open or closed as a new install.Since the valleys conduct much more water than the field of the roof I like to dry in the area as soon as its ripped out and cleaned.With changing weather patterns even during the course of a single day I know I don't have to panic if a sudden shower strikes,I'm already dried in.
Even if the felt does disintegrate over time I feel better knowing I've used it,especially since its cost in dollars and time is minimal.
If I were doing the roof from scratch I'd use it so I do even on replacement valleys.
|Posted on Friday, September 03, 2004 - 06:55 pm: ||
You can also replace a closed valley by removing just one side of the valley and just a few slate from the other side. most closed valleys seem to have one nail per diamond shape flashing and if your lucky the roofer before you was consistent in his nailing pattern (all nailed in the upper left or upper right)I have found this to work on quite a few closed valleys,but every once in a while you do have to remove both sides because of tar or many broken slates or random nailing,I try to make my diamonds as large as possible to help flash any slate slots(where the slate but together) that may be close to the valley,start at the top (number your rows)and remove slate to the bottom, you can also remove just half of the valley if weather threatens,start installing your new diamonds near the middle of the valley and work your way up then finish the bottom half as weather permits.If the valley has been a persistent leaker you are better off removing both sides of the valley to inspect your wood and to make sure the slate are in good sound condition ect..I do not know if this is true else where but here in the Pittsburgh area many of the slate roofs with closed valleys have shorter slates 12" to 18" in length.Why I do not Know? Felt is used most of the time but not all the time as mentioned above. I really like the look of a closed valley and it is such a simple yet effective method of valley flashing. Good Luck.