Windy Knoll Observatory - My Build Thread

[Scorpius]

Ever try to build an observatory in the midst of a hurricane? http://www.cnn.com/2015/10/01/us/hurricane-joaquin/index.html Me neither & don't think I'll try. Forgot to grab a pic but went over to the obsy site last evening to check on things and the huge tarp I used to cover the entire thing had come loose on one corner and the floor had gotten slightly wet in that area from the torrential rain that soaked the area on Tues. Wasn't too bad though so think I caught it in time. Went ahead and tied it down more sercurely so all I can do now is keep my fingers crossed the tarp stays in place over the next few days. It's not like I'm worried the floor system it's going to blow away or anything but I am concerned the un-sealed plywood flooring could delaminate if exposed to an extended period of heavy rain.

Oh well, guess all that remains is to hope the storm moves through quickly and the winds don't get too high this far west however, it sounds like we're definitely going to experience more heavy rainfall no matter how the storm tracks so construction remains at a standstill for at least several more days - but hopefully no longer than the weekend following the one coming up...

Let's all pray this thing moves out to sea and the residents up & down the east coast are spared another superstorm like Sandy which devestated areas not far north of here in 2012...

[Stevp]

Heres hoping that all is well!

[Scorpius]

Heres hoping that all is well!

Thanks Steve - I really appreciate that.   We should be fine here as we’re 200 miles from the ocean & west of the Blue Ridge so it’s the safety of folks along the coast that’s the major concern.

For us, it’s usually flash flooding that’s the problem. Hurricane Fran in ’96 caused a lot of damage but by far the worst hurricane in history for this area was Camille back in ’69. I was 10 yrs. old & still remember listening to the reports come in over an old transistor radio. The highest death toll from Camille - which made landfall in Mississippi - was in Nelson County, VA, just one county east of Augusta where I live (we’re fully west of the Blue Ridge but Nelson straddles the mountain). Most of the fatalities were on the eastern slopes & resulted from blunt trauma injuries associated with mud slides – not drowning. Entire mountain sides were washed away & evidence of the devastation can still be seen in places where the sides of mountains are nothing but bed rock.

To give you an idea just how bad Camille was, here’s a copy/paste from Wikipedia describing the devastation.

“but the worst was in Nelson County where 27 inches (690 mm) fell. There, rainfall was so heavy that reports were received of birds drowning in trees, cows floating down the Hatt Creek and of survivors having to cup hands around their mouth and nose in order to breathe through the deluge. Though the official rainfall was recorded as 27 inches, unofficial estimates are much greater. Some estimate that more than 40 inches of rain fell at Davis Creek. Most gauges were washed away; however, it was reported that an empty 55 gallon drum that was not even in the center of the heaviest rainfall had 31 inches of water in it after Camille passed. So much rain fell in such a short time in Nelson County that, according to the National Weather Service at the time, it was the probable maximum rainfall which meteorologists compute to be theoretically possible.”

Although it looks like the rain from Joaquin will be certainly be heavy here, thankfully nothing like that is forecast for us with this storm so it’s the areas along the coast that appear to be more in jeopardy. All we can do is hope it’s not going to be as bad as it could be and pray for better weather once it’s all over.

Here’s wishing you clear skies my friend & quick progress with your ongoing observatory build… 

Scorpius

https://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/08/19/unprecedented-rain-hurricane-camilles-deadly-dlood-in-the-blue-ridge-mountains/

[Scorpius]

They won't get stuck on it so it won't hurt them. But they will not like getting covered in the goo. I like mices but not in my gear.

Hey Derek - check this out:

http://greatstuff.dow.com/pestblock/

Looks like just what the doctor ordered - think it would work?

[Tim99]

I really enjoyed seeing your pictures and reading about your plan for your observatory.  It's got me thinking........

Good luck with your project.

[Scorpius]

I really enjoyed seeing your pictures and reading about your plan for your observatory.  It's got me thinking........

Good luck with your project.

Thanks Tim - hope to have some new progress pics to post after the weekend so stay tuned...

[Physopto]

Hey Derek - check this out:

http://greatstuff.dow.com/pestblock/

Looks like just what the doctor ordered - think it would work?

Hi Scorpius,

I think it is the same sort of stuff, the "low expansion" is very important or it may cause bending of structures. You cannot use ordinary expanding foam. it will come down to availability and cost. Soudal stays soft to the touch and you get about 25 litres from a tube. It can be bought in several different forms. One is as in the video you pointed out. But you get less out of a can and it is way more expensive. The other methods require a  foam gun and a cleaner  for the gun. (Use immediately or the gun is very difficult to clean!!!) About £25  here so around $40  over at your end. The guns come in two types. Bayonet and Screw. Initial cost higher because of the guns. But if you use a lot it works out cheaper. You can use the foam for insulation in the cavity between

walls. You are on the right track.

Derek

[Scorpius]

After a long weekend of hard work, all the walls are framed except two side walls for the pod. Also have two more roof rafters to install before the plywood, tar paper & shingles can be put down.  Hope to finish these odds & ends after work this week & be ready to start installing wall sheathing this coming weekend. Then once that’s complete, it will be time to set a few more posts & start on the rolling roof.

Keeping my fingers crossed the weather stays decent for at least another month so I can get this observatory structure under roof before the first snow!

[Dark Horizon]

That's a hell of a big pier base.... looks like it's gonna be nice. Bit envious of you're aspect; pretty good that.

[JohnC64]

Hi Scorpius,

Thats looking very nice and very solid looking too.

Cheers John

[Scorpius]

That's a hell of a big pier base.... looks like it's gonna be nice. Bit envious of you're aspect; pretty good that.

Yeah, There's a lot of concrete in that pier base (about 1.5 cu yd) – which is likely more than necessary - but my thought is too much is better than not enough. I’ve got pretty good horizons in all directions so wall height ends up being  my limiting factor. Did some testing the other night with 8” SCT in place & estimate my lowest altitude will be about 20 degrees which should be sufficient for imaging due to the limiting effects of atmosphere. Hope to someday upgrade to a better mount & larger scope so the plan is to add a pier extension should wall height become an issue.

Hi Scorpius,

Thats looking very nice and very solid looking too.

Cheers John

Thanks John. Still a ways to go but slowly getting there. How bout you - is your obsy up & running? Any first light photos to share? 

Edited October 22, 2015 by Scorpius

[Tim99]

I have enjoyed looking at your pictures of the pier project.  This is a first-rate job you are doing!  Looking forward to seeing the finished project.

[Dark Horizon]

Sounds like a good plan to me. I'll keep my eye on the thread. it's interesting to see how others solve problems along the way. Makes my life easier and my brain hurt less!

Good luck!

[Scorpius]

I have enjoyed looking at your pictures of the pier project.  This is a first-rate job you are doing!  Looking forward to seeing the finished project.

Thanks Tim, it’s turned out to be quite an undertaking due in part to my tendency to over-engineer things and my aversion to taking short cuts. This observatory is being built as a permanent structure with methods similar to those used in home building. For example, it’s tied to the ground with treated 4x6 posts supported by pre-cast concrete pier footings set below frost line as opposed to blocks laid on top of the ground. The floor joists are 2x8’s – 16” on center - with double band boards around the entire perimeter and the ends of all joists are secured with metal joist hangers. There are metal tie-down straps that secure the floor system to the posts and the inside corners are reinforced with metal corner brackets. The flooring is 3/4 inch plywood with construction adhesive applied on top of each joist prior to nailing . The floor has two coats of exterior grade primer and a topcoat of slip resistant exterior porch floor paint (a second coat will be added once construction is complete). The walls are 2x4’s – 16” on center - with single bottom plates (fastened with construction adhesive and 16d nails) & double top plates - except the two walls that will carry the roof have single top plates with 4x4’s placed on top with construction adhesive and screws. The ends of the 4x4’s are notched to accept the top plate of the adjoining wall and the joint is fastened with construction adhesive and 16d nails. This locks the corners together eliminating the possibility they might come apart in the future. All the vertical corners are made with field constructed corner posts which consist of 2 full studs with 2x4 blocks sandwiched between so the end stud of the perpendicular wall can be securely fastened. This makes the corners stronger and provides a nailing surface in both directions for ease of installing wall covering should I ever decide to cover the interior walls. The door and pod openings have double studs on both sides and the single top plate + 4x4 arrangement forms the header.

The outside will be covered with exterior grade, 5/8” sheathing (we call it T-111 in the US) and 30 lb. roofing felt (tar paper) will form the vapor barrier between siding and studs since I refuse to pay $150 for a roll of Tyvek house wrap. The siding will be coated with an exterior stain/waterproofing product like that used on decks.

Basically, it’s built like a fortress which is my preferred method for any structure I decide to tackle. However, I have no experience building a rolling roof so this is something new that will require some additional planning and unconventional construction techniques. Think I can handle it but at this point that remains to be seen...

Sounds like a good plan to me. I'll keep my eye on the thread. it's interesting to see how others solve problems along the way. Makes my life easier and my brain hurt less!

Good luck!

Thanks for the words of encouragement and I must admit - Not only does my brain hurt but so do my back and shoulders! But I think it'll be worth it in the end...

[Scorpius]

Not sure why I decided to post that nuts & bolts account of how the building is put together unless I was thinking it might help someone else along the way. Probably sounded like I was bragging but didn't mean to come across that way. At any rate, one thing I forgot to mentiion is the pod roof is built with 2x4 rafters - spaced 12" on center - supported with skewable metal joist hangers on the upper side and tied to the top plate of the short wall with metal rafter tie downs. It will have a 6" overhang along the 3 open sides before installing 1/2" roof sheathing that gets drip edge around the perimeter before applying a layer of 30 lb. roofing felt. Then the pod roof will be covered with standard asphalt shingles (probably green to match the gazebo) 

Also wanted to mention the plywood flooring was screwed down - not nailed as previously stated.

Weather has been the biggest factor with over a week of heavy rain a month or so back but it's been absolutely gorgeous this week but of course I work 8-5, Mon-Fri. But now it's calling for a 50% chance of rain on Sun. and the days are getting much shorter so can only manage to get in a couple hours after work before it's too dark to see what I'm doing. Then the time changes on Nov. 1 which means it will already be dark by the time I get home eliminating the chance to do anything at all during the week. So as I've mentioned before, I'm under a real time crunch to get it under roof and weather will have a big impact on how productive the weekends will be from here on out. Got a birthday coming up in mid-Nov so will probably ask for the day off so I can work on the obsy. Don't want to end up with an observatory with a floor & 4 walls - but no roof - so keeping my fingers crossed bad weather will hold off at least until after Thanksgiving. Hoping to be able to use it some this winter leaving the gear set-up even though it will be far from complete...

[MikeP]

Probably sounded like I was bragging

There is a big difference between bragging and just being proud of what you have built.  I'm positive you are in the latter camp. 

I'm enjoying your build and I'm very impressed with your attention to detail.  Good luck with the weather and your roof design.

Mike

[JimStanley]

It's great following the build progress, thanks for posting such detail, it is really appreciated. Good luck with the project, I will following with interest.

[Scorpius]

It's great following the build progress, thanks for posting such detail, it is really appreciated. Good luck with the project, I will following with interest.

Thanks Jim, I really enjoy posting updates because it helps keep me motivated knowing folks are interested in Windy Knoll’s progress. Things are moving along nicely. In the evenings last week - the two pod side walls were framed & yesterday - the side overhangs were finished, the roof sheathing was laid, & roof felt + drip edge was installed. Then the shingles were finished up by the light of a headlamp & I’m pretty darn excited the pod now has a roof! I’ll come back later & install the lower soffit boards which will finish closing up the pod roof to keep the critters out. They’re calling for a chance of rain today but looks like it might go around us so the plan is to get some tar paper (moisture barrier) on the walls so the siding can start going up.

I wanted to keep the pod opening as high as possible but if you notice in the pics, the pod roof comes almost all the way to the top of the 4x4 where the roller tracks will mount. I’m a little concerned about clearance from the rolling roof to the pod roof but if I build the rolling roof on 4x4’s I think I’ll be ok. Anyone have any thoughts or suggestions in that regard?

[Pan Euro]

That looks really impressive.

[malc-c]

Fantastic construction... really solid.

Keep the updates coming...

[r3i]

Great progress, it's looking very smart.

[Scorpius]

That looks really impressive.

Fantastic construction... really solid.

Keep the updates coming...

Great progress, it's looking very smart.

Thanks guys - still just plugging along... 

Got all the vapor barrier installed today. It’s 30 lb. roofing felt (the heavy stuff) & although house wrap is often used, this is an old school method of isolating the interior from any moisture that might wick through the siding  (plus it’s a lot less expensive). It took two 75 ft rolls & the silver stuff is window flashing tape. One roll of tape didn’t go very far & now I’m wondering if it’s really necessary in the first place. Started with the bottom row & overlapped the horizontal joints about 3”. The corners are overlapped as well & just let it run long at the top for now.

Putting this up makes it feel more like a building inside & I’m anxious to get started on the siding. However, that may not happen until next weekend since rain is forecast for Tues & Wed. Feel like I’m finally getting somewhere but obviously - still need a roof before the mount & scope can be left on the pier. But at least I’ve got a pod with a roof to keep the dew off should I decide to set up the gear before the main roof is complete.

[Physopto]

What is holding the roofing felt on the walls? Are they galvanised  nails? If so could I suggest you paint each one with some protective rubber solution. May sound like over doing it but any moisture over a period of time (could be a long time)  will eventually cause corrosion, especially if there is not a good air flow to dry out the moisture. Here in the UK we have found that galvanised ties in our house walls have been the causation of house sales being very expensive. Mortgage companies now ( in the last 20 years ) want them all replaced with stainless steel ties before they will allow the sales to go ahead, simply because of corrosion tie failure. This has happened in properties as young as 10/15 years old. Costs are around £2000 per property. Why take the chance if it can be prevented.

Your build looks really nice. It will be good to see the end result.

Derek

[Scorpius]

What is holding the roofing felt on the walls? Are they galvanised  nails? If so could I suggest you paint each one with some protective rubber solution. May sound like over doing it but any moisture over a period of time (could be a long time)  will eventually cause corrosion, especially if there is not a good air flow to dry out the moisture. Here in the UK we have found that galvanised ties in our house walls have been the causation of house sales being very expensive. Mortgage companies now ( in the last 20 years ) want them all replaced with stainless steel ties before they will allow the sales to go ahead, simply because of corrosion tie failure. This has happened in properties as young as 10/15 years old. Costs are around £2000 per property. Why take the chance if it can be prevented.

Your build looks really nice. It will be good to see the end result.

Derek

Hi Derek – never heard of this before but thanks for the tip. These are the nails I used and yes they’re galvanized. Wonder why they would make these for installing house wrap & roof felt if this is a common issue?

http://www.lowes.com/ProductDisplay?partNumber=109265-54622-RPCHDRS1-300&langId=-1&storeId=10151&productId=50329391&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

What exactly is the problem? Do they just get a little rusty over time or cause something more serious like structural damage. I do know using galvanized fasteners in treated wood (like decks) can rust them out but just nailing felt to untreated studs wouldn’t seem like a big deal. However, maybe I’m just being stubborn & wanting to avoid going back & coating 100’s of nail heads with some sort of waterproofing compound? 

[Tinker1947]

Its a bit late but my vapour barrier is held in place with stainless steel staples, the wood or plastic overcoat will stop and moisture i would think it will be fine with or without  any treatment....