Spotted Gum feature deck - Advice needed

Hi All,

I am looking at putting in a 22sqm deck of which 15sqm will be under the alfresco and the remaining 7sqm will be be the area between alfresco and pool fence/gate. This 7sqm will obviously be fully exposed.

I am going with a spotted gum feature deck (135 x 19) and just had the following questions:

1: Should be concerned that the timber is “feature” opposed to a standard or premium timber?
2: Should I be concerned that 7sqm of the deck will be fully exposed?
3: Would the 135x19 timber be my susceptible to “cupping”?

Thanks in advance.

Cheers,
Robbie

 

1. No, spotted gum is a good decking timber.

2. No, but you will need to oil/coat the timber and REGULARLY maintain it by washing and reapplying oil every 6-12 months. This is essential, don't skimp on it.

3. Maybe, but you can reduce the riak by installing the boards properly and regularly maintaining them. 135mm is quite wide for decking boards. Make sure your joists are adequately spaced, and you fix the boards with at least 2 screws/nails per joist - roughly 20mm in from the edge of each board. A competent carpenter should be all over this.

 

Who else lives in the area? Some friends of mine bought a place with a deck in a hilly treed part of town. The cockatoos munched large portions of the deck . Be sure to ponder how to deter such events from happening. From memory my friends have an assortment of rubber snakes on the deck to try and scare off the cockatoos

 

Thanks for feedback, much appreciated.

Also, what could be done to ensure the under deck between alfresco and pool stays dry underneath? After heavy rains it can get boggy there, mainly due to being uncovered as well as when the pool is full there is a bit of overflow into that area.

Could i look at adding some drainage? As per arrows in the pic, there are drainage pipes about 2-3m from the deck, so i could possibly divert any excess water into them?

 

From the photo, it looks like you don't have much fall...You'll never be able to keep the area beneath the deck dry, you just need to manage the water.

Without knowing your block, I would suggest excavating about 150mm below the deck and backfilling with 20mm gravel. This at least would create a sump and keep the water away from your bearers/joists.

Re: diverting water into the existing drainage - this depends on your circumstances. If they are existing stormwater drains, then it's probably fine. However, DO NOT divert run-off into a sewer pipeline. This is not only illegal, it could have unpleasant consequences for you in the future!

The best thing to do may be lay some new ag drain or similar to take the water to the street or into the stormwater network.

EDIT: obviously, make sure your bearers and joists are H4 treated (or steel). You sould also install a plastic barrier strip (not sure what it's called??) on top of your joists ie: between joists and decking boards. This will divert water away from the joists.

 

Remember to have the posts of the deck sitting in metallic stirrups (ie don't have the timber sitting in the soil, with concrete or otherwise. Create separation with stirrups to avoid wood rot and termites

 

1: Should be concerned that the timber is “feature” opposed to a standard or premium timber?
Not at all! I actually prefer feature grade timber - its the reason timber looks so great

2: Should I be concerned that 7sqm of the deck will be fully exposed?
No, but be sure to stay on top of that oiling maintenance OR just leave the timber to silver/grey off

3: Would the 135x19 timber be my susceptible to “cupping”?
Yes, it will inevitably cup over time